Smaller sub-band size for PMI than for CQI

ABSTRACT

Abstract: A method performed by a wireless device ( 510 ,  700 ,  1100 ) is disclosed. The wireless device obtains ( 601 ) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines ( 602 ) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits ( 603 ), to a network node ( 560 ,  1000 ), the determined CSI feedback.

TECHNICAL FIELD

The present disclosure relates, in general, to wireless communicationsand, more particularly, to independent sub-band size for precodingmatrix indicator and channel quality indicator.

BACKGROUND

Multi-antenna techniques can significantly increase the data rates andreliability of a wireless communication system. Equipping both thetransmitter and the receiver with multiple antennas results in amultiple-input multiple-output (MIMO) communication channel thatimproves performance. Such systems and/or related techniques arecommonly referred to as MIMO.

The New Radio (NR) standard is currently evolving with enhanced MIMOsupport. A core component in NR is the support of MIMO antennadeployments and MIMO-related techniques, such as spatial multiplexing.The spatial-multiplexing mode aims for high data rates in favorablechannel conditions.

FIG. 1 illustrates a transmission structure 100 of precoded spatialmultiplexing mode in NR. In the spatial multiplexing operation depictedin FIG. 1 , the information carrying symbol vector s is multiplied by anN_(T) × r precoder matrix W, which serves to distribute the transmitenergy in a subspace of the N_(T) (corresponding to N_(T) antenna ports)dimensional vector space. The precoder matrix is typically selected froma codebook of possible precoder matrices. The precoder matrix istypically indicated by means of a precoder matrix indicator (PMI), whichspecifies a unique precoder matrix in the codebook for a given number ofsymbol streams. The transmission rank (r) symbols in symbol vector seach correspond to a layer. In this way, spatial multiplexing isachieved since multiple symbols can be transmitted simultaneously overthe same time/frequency resource element (TFRE). The number of symbols ris typically adapted to suit the current channel properties.

NR uses orthogonal frequency division multiplexing (OFDM) in thedownlink (DL) and discrete Fourier transform (DFT) precoded OFDM in theuplink (UL). Hence, the received N_(R) × 1 vector y_(n) for a certainTFRE on subcarrier n (or alternatively data TFRE number n) is thusmodeled by:

y_(n) = H_(n)Ws_(n) + e_(n)

where e_(n) is a noise/interference vector obtained as realizations of arandom process. The precoder W can be a wideband precoder, which isconstant over frequency, or precoder W can be frequency selective.

The precoder matrix W is often chosen to match the characteristics ofthe N_(R)×N_(T) MIMO channel matrix H_(n), resulting in so-calledchannel dependent precoding. This is also referred to as closed-loopprecoding and essentially strives to focus the transmit energy into asubspace that is strong in the sense of conveying much of thetransmitted energy to the user equipment (UE).

In closed-loop precoding for the NR DL, the UE transmits recommendationsto the base station (e.g., a gNodeB (gNB) in NR) of a suitable precoderto use. The UE bases these recommendations on channel measurements inthe forward link (DL). In the case of NR, the gNB configures the UE toprovide feedback according to CSI-ReportConfig. The gNB may transmitchannel state information reference signals (CSI-RS) and may configurethe UE to use measurements of CSI-RS to feed back recommended precodingmatrices that the UE selects from a codebook. A single precoder that issupposed to cover a large bandwidth (wideband precoding) may be fedback. It may also be beneficial to match the frequency variations of thechannel and instead feed back a frequency-selective precoding report(e.g., several precoders, one per sub-band). This is an example of themore general case of channel state information (CSI) feedback, whichalso encompasses feeding back other information than recommendedprecoders to assist the gNB in subsequent transmissions to the UE. Suchother information may include channel quality indicators (CQIs) as wellas transmission rank indicator (RI). In NR, CSI feedback can be eitherwideband, where one CSI is reported for the entire channel bandwidth, orfrequency-selective, where one CSI is reported for each sub-band, whichis defined as a number of contiguous resource blocks (RBs) rangingbetween 4-32 physical resource blocks (PRBs), depending on the bandwidthpart (BWP) size.

Given the CSI feedback from the UE, the gNB determines the transmissionparameters it wishes to use to transmit to the UE, including theprecoding matrix, transmission rank, and modulation and coding scheme(MCS). These transmission parameters may differ from the recommendationsthat the UE makes. The number of columns of the precoder W reflects thetransmission rank, and thus the number of spatially multiplexed layers.For efficient performance, it is important to select a transmission rankthat matches the channel properties.

Two-Dimensional Antenna Arrays

Two-dimensional (2D) antenna arrays may be (partly) described by thenumber of antenna columns corresponding to the horizontal dimensionN_(h), the number of antenna rows corresponding to the verticaldimension N_(v), and the number of dimensions corresponding to differentpolarizations Np. The total number of antennas is thus N =N_(h)N_(v)N_(p). Note that the concept of an antenna is non-limiting inthe sense that it can refer to any virtualization (e.g., linear mapping)of the physical antenna elements. For example, pairs of physicalsub-elements could be fed the same signal, and hence share the samevirtualized antenna port.

FIG. 2 illustrates a two-dimensional antenna array of cross-polarizedantenna elements. More particularly, FIG. 2 illustrates an example of a4x4 antenna array 200 with cross-polarized antenna elements. In theexample of FIG. 2 , the two-dimensional antenna array of cross-polarizedantenna elements (N_(P) = 2) has N_(h) = 4 horizontal antenna elementsand N_(v) = 4 vertical antenna elements.

Precoding may be interpreted as multiplying the signal with differentbeamforming weights for each antenna prior to transmission. One approachis to tailor the precoder to the antenna form factor (i.e., taking intoaccount N_(h), N_(v) and N_(p) when designing the precoder codebook).

Channel State Information Reference Signals (CSI-RS)

For CSI measurement and feedback, CSI-RS are defined. A CSI-RS istransmitted on each transmit antenna (or antenna port) and is used by aUE to measure the DL channel between each of the transmit antenna portsand each of its receive antenna ports. The antenna ports are alsoreferred to as CSI-RS ports. The number of antenna ports currentlysupported in NR are {1,2,4,8,12,16,24,32}. By measuring the receivedCSI-RS, a UE can estimate the channel that the CSI-RS is traversing,including the radio propagation channel and antenna gains. The CSI-RSfor the above purpose is also referred to as Non-Zero Power (NZP)CSI-RS.

CSI-RS can be configured to be transmitted in certain slots and incertain resource elements (REs) in a slot.

FIG. 3 illustrates an example of RE allocation for a 12-port CSI-RS inNR 300. In the example of CSI-RS REs for 12 antenna ports illustrated inFIG. 3 , one RE per RB per port is shown.

In addition, an interference measurement resource (IMR) is also definedin NR for a UE to measure interference. An IMR contains 4 REs, either 4adjacent RE in frequency in the same OFDM symbol or 2 by 2 adjacent REsin both time and frequency in a slot. By measuring both the channelbased on NZP CSI-RS and the interference based on an IMR, a UE canestimate the effective channel and noise plus interference to determinethe CSI (i.e., rank, precoding matrix, and the channel quality).

Furthermore, a UE in NR may be configured to measure interference basedon one or multiple NZP CSI-RS resources.

CSI Framework In NR

In NR, a UE can be configured with multiple CSI reporting settings andmultiple CSI-RS resource settings. Each resource setting can containmultiple resource sets, and each resource set can contain up to 8 CSI-RSresources. For each CSI reporting setting, a UE feeds back a CSI report.

Each CSI reporting setting may contain some or all of the followinginformation: a CSI-RS resource set for channel measurement; an IMRresource set for interference measurement; a CSI-RS resource set forinterference measurement; time-domain behavior (i.e., periodic,semi-persistent, or aperiodic reporting); frequency granularity (i.e.,wideband or sub-band); CSI parameters to be reported such as RI, PMI,CQI, and CSI-RS resource indicator (CRI) in case of multiple CSI-RSresources in a resource set; codebook types (i.e., Type I or Type II);codebook subset restriction; measurement restriction; and sub-band size.With respect to sub-band size, one out of two possible sub-band sizes isindicated. The value range depends on the bandwidth of the BWP. OneCQI/PMI (if configured for sub-band reporting) is fed back per sub-band.

When the CSI-RS resource set in a CSI reporting setting containsmultiple CSI-RS resources, one of the CSI-RS resources is selected by aUE and a CSI-RS Resource Indicator (CRI) is also reported by the UE toindicate to the gNB about the selected CSI-RS resource in the resourceset, together with RI, PMI and CQI associated with the selected CSI-RSresource.

For aperiodic CSI reporting in NR, more than one CSI reporting setting,each with a different CSI-RS resource set for channel measurement and/orresource set for interference measurement can be configured andtriggered at the same time. In this case, multiple CSI reports areaggregated and sent from the UE to the gNB in a single Physical UplinkShared Channel (PUSCH).

DFT-Based Precoders

One type of precoding uses a DFT-precoder, where the precoder vectorused to precode a single-layer transmission using a single-polarizeduniform linear array (ULA) with N antennas is defined as:

$w_{1D}(k) = \frac{1}{\sqrt{N}}\begin{bmatrix}e^{j2\pi \cdot 0 \cdot \frac{k}{QN}} \\e^{j2\pi \cdot 1 \cdot \frac{k}{QN}} \\ \vdots \\e^{j2\pi \cdot {({N - 1})} \cdot \frac{k}{QN}}\end{bmatrix},$

where k = 0,1,... QN - 1 is the precoder index and Q is an integeroversampling factor. A corresponding precoder vector for atwo-dimensional uniform planar array (UPA) can be created by taking theKronecker product of two precoder vectors as:

w_(2D)(k, l) = w_(1D)(k) ⊗ w_(1D)(l).

Extending the precoder for a dual-polarized UPA may then be done as:

$\begin{array}{l}{w_{2D,DP}( {k,l,\phi} ) = \lbrack \begin{array}{l}1 \\e^{j\phi}\end{array} \rbrack \otimes w_{2D}( {k,l} ) = \lbrack \begin{array}{l}{w_{2D}( {k,l} )} \\{e^{j\phi}w_{2D}( {k,l} )}\end{array} \rbrack =} \\{\lbrack \begin{array}{ll}{w_{2D}( {k,l} )} & 0 \\0 & {w_{2D}( {k,l} )}\end{array} \rbrack\lbrack \begin{array}{l}1 \\e^{j\phi}\end{array} \rbrack,}\end{array}$

where e^(jϕ) is a co-phasing factor that may, for instance, be selectedfrom Quadrature Phase Shift Keying (QPSK) alphabet

$\phi \in \{ {0,\frac{\pi}{2},\pi,\frac{3\pi}{2}} \}.$

A precoder matrix W_(2D,DP) for multi-layer transmission may be createdby appending columns of DFT precoder vectors as:

$\begin{array}{l}{W_{2D,DP} =} \\{\lbrack \begin{array}{llll}{w_{2D,DP}( {k_{1},l_{1},\phi_{1}} )} & {w_{2D,DP}( {k_{2},l_{2},\phi_{2}} )} & \cdots & {w_{2D,DP}( {k_{R},l_{R},\phi_{R}} )}\end{array} \rbrack,}\end{array}$

where R is the number of transmission layers (i.e., the transmissionrank). In a special case for a rank-2 DFT precoder, k₁ = k₂ = k and l₁ =l₂ = l, meaning that:

$\begin{array}{l}{W_{2D,DP} = \lbrack \begin{array}{ll}{w_{2D,DP}( {k,l,\phi_{1}} )} & {w_{2D,DP}( {k,l,\phi_{2}} )}\end{array} \rbrack =} \\{\lbrack \begin{array}{ll}{w_{2D}( {k,l} )} & 0 \\0 & {w_{2D}( {k,l} )}\end{array} \rbrack\lbrack \begin{array}{ll}1 & 1 \\e^{j\phi_{1}} & e^{j\phi_{2}}\end{array} \rbrack.}\end{array}$

Such DFT-based precoders are used, for example, in NR Type I CSIfeedback.

Multi-User MIMO (MU-MIMO)

With MU-MIMO, two or more users in the same cell are co-scheduled on thesame time-frequency resource. That is, two or more independent datastreams are transmitted to different UEs at the same time, and thespatial domain is used to separate the respective streams. Bytransmitting several streams simultaneously, the capacity of the systemcan be increased. This, however, comes at the cost of reducing thesignal-to-interference-plus-noise ratio (SINR) per stream, as the powermust be shared between streams and the streams will cause interferenceto each-other.

Multi-Beam (Linear Combination) Precoders

One central part of MU-MIMO is obtaining accurate CSI that enablesnullforming between co-scheduled users. Therefore, support has beenadded in Long Term Evolution (LTE) Release 14 (Rel-14) and NR Release 15(Rel-15) for codebooks that provide more detailed CSI than thetraditional single DFT-beam precoders. These codebooks are referred toas Advanced CSI (in LTE) or Type II codebooks (in NR) and can bedescribed as a set of precoders where each precoder is created frommultiple DFT beams. A multi-beam precoder may be defined as a linearcombination of several DFT precoder vectors as:

$w = {\sum\limits_{i}{c_{i} \cdot w_{2D,DP}( {k_{i},l_{i},\phi_{i}} )}},$

where {c_(i)} may be general complex coefficients. Such a multi-beamprecoder may more accurately describe the UE’s channel and may thusbring an additional performance benefit compared to a DFT precoder,especially for MU-MIMO where rich channel knowledge is desirable inorder to perform nullforming between co-scheduled UEs.

NR Rel-15

For the NR Type II codebook in Rel-15, the precoding vector for eachlayer and sub-band is expressed in 3^(rd) Generation Partnership Project(3GPP) TS 38.214 v15.3.0 as:

$\begin{array}{l}{W_{q_{1},q_{2},n_{1},n_{2},p_{l}^{(1)},p_{l}^{(2)},c_{l}}^{l} =} \\{\frac{1}{\sqrt{N_{1}N_{2}{\sum\limits_{i = 0}^{2L - 1}( {p_{l,i}^{(1)}p_{l,i}^{(2)}} )^{2}}}}\lbrack \begin{array}{l}{\sum\limits_{i = 0}^{L - 1}{v_{m_{1}^{(i)},m_{2}^{(i)}}p_{l,i}^{(1)}p_{l,i}^{(2)}\varphi_{l,i}}} \\{\sum\limits_{i = 0}^{L - 1}{v_{m_{1}^{(i)},m_{2}^{(i)}}p_{l,i + L}^{(1)}p_{l,i + L}^{(2)}\varphi_{l,i + L}}}\end{array} \rbrack,l = 1,2}\end{array}$

By restructuring the above formula and expressing it more simply, theprecoder vector w_(l,p)(k) can be formed for a certain layer l = 0,1,polarization p = 0,1 and resource block k = 0, ..., N_(RB) -1, as:

$w_{l,p}(k) = \frac{1}{C}{\sum\limits_{i = 0}^{L - 1}{v_{i}p_{l,i}^{(1)}c_{l,i}(k)}}$

where

$c_{l,i}(k) = p_{l,i}^{(2)}( \lfloor \frac{k}{s} \rfloor )\varphi_{l,i}( \lfloor \frac{k}{s} \rfloor )\text{for}p = 0$

and

$c_{l,i}(k) = p_{l,L + i}^{(2)}( \lfloor \frac{k}{s} \rfloor )\varphi_{l,L + i}( \lfloor \frac{k}{s} \rfloor )\text{for p = 1}$

, S is the sub-band size and N_(SB) is the number of sub-bands in theCSI reporting bandwidth. Hence, the change in a beam coefficient acrossfrequency c_(l,) _(i)(k) is determined based on the 2N_(SB) parameters

p_(l, i)⁽²⁾(0), …, p_(l, i)⁽²⁾(N_(SB) − 1)

and

φ_(l, i)(0), …, φ_(l, i)(N_(SB) − 1)

where the sub-band amplitude parameter

p_(l, i)⁽²⁾

is quantized using 0-1 bit and the sub-band phase parameter φ_(l,i) isquantized using 2-3 bits, depending on codebook configuration.

Type II Overhead Reduction For NR Release 16 (Rel-16)

The Type II CSI feedback performance and overhead is sensitive to thesub-band size. The optimal Type II CSI beam coefficients can vary quiterapidly over frequency, and hence the more averaging that is performed(i.e., the larger the sub-band size), the more reduction in MU-MIMOperformance can be expected. Operation with Type II CSI is typicallycompared against reciprocity-based operation, where subcarrier-level CSIcan be obtained via SRS sounding. In the NR CSI reporting procedure,there are two possible CSI sub-band sizes defined for sub-band based CSIreporting for each number of PRBs of the BWP (i.e., the BWP bandwidth)and the gNB configures which of the two sub-band sizes to use as part ofthe CSI reporting configuration. For 10 MHz bandwidth using 15 kHzsubcarrier spacing (SCS), which is a typical LTE configuration, NRfeatures either seven 1.44 MHz sub-bands or thirteen 720 kHz sub-bands.However, for 100 MHz bandwidth using 30 kHz SCS, a typical NRconfiguration, NR features either nine 11.52 MHz sub-bands or eighteen5.76 MHz sub-bands. Such large sub-band sizes could result in poor CSIquality.

Overhead reductions are considered for NR Rel-16 Type II. The rationaleis that it has been observed that there is a strong correlation betweendifferent values of c_(l,i)(k), for different values of k, and thiscorrelation could be exploited to perform efficient compression of theinformation in order to reduce the number of bits required to representthe information. This would lower the amount of information that needsto be signaled from the UE to the gNB, which is relevant from severalaspects. Both lossy (implying a potentially decreased level of qualityin the CSI) as well as lossless compression may be considered.

In the case of lossy compression, there are many ways to parametrize thebeam coefficients over frequency to achieve an appropriate CSI qualityvs. overhead trade-off. By keeping the basic structure of the precoderas described above, one may update the expression for c_(l,i)(k) . Moregenerally, one can describe c_(l,i)(k) as a function f(k, α₀, ...,α_(M-1)) that is based on the M parameters α₀, ..., α_(M-1), where theseM parameters in turn are represented using a number of bits that can befed back as part of the CSI report.

As an example, consider the special case where f(k, α₀, ..., α_(M-1))constitutes a linear transformation. In this case, the function can beexpressed by using a transformation matrix:

$B = \begin{bmatrix}b_{0,0} & \cdots & b_{0,K} \\ \vdots & \ddots & \vdots \\b_{N_{RB},0} & \cdots & b_{N_{RB},K}\end{bmatrix} = \lbrack {b_{0}\ldots b_{K}} \rbrack,$

consisting of K number of N_(RB) × 1 sized basis vectors along with acoefficient vector:

$a = \begin{bmatrix}a_{0} \\\cdots \\a_{K - 1}\end{bmatrix}.$

Here, N_(RB) is the number of resource blocks in the CSI reportingbandwidth Other granularities and units of the basis vectors can also beconsidered, such as the number of sub-bands N_(SB), a subcarrier levelgranularity with 12N_(RB) × 1 size basis vectors, or a number of RBs.

For instance, the M parameters can be split up into a parameter I,selecting the K basis vectors from a set of basis vector candidates, andthe coefficients a₀, ..., a_(K-1). That is, some index parameter Idetermines the basis matrix B, for instance, by selecting columns from awider matrix or by some other way. The beam coefficients may then beexpressed as:

$c_{l,i}(k) = f( {k,I,a_{0},\mspace{6mu}\ldots\mspace{6mu},a_{K - 1}} ) = \lbrack B\rbrack_{k,:}a = {\sum\limits_{d = 0}^{K - 1}{b_{k,d}a_{d}}}.$

That is, by forming a vector with all the beam coefficients (for a beam)such as:

$c_{l,i} = \begin{bmatrix}{c_{l,i}(0)} \\\cdots \\{c_{l,i}( {N_{RB} - 1} )}\end{bmatrix},$

that vector can be expressed as a linear transformation:

c_(l, i) = Ba_(i)

In fact, the entire precoder can be expressed using matrix formulation,which is good for illustrative purposes. The beam coefficients for allthe beams i and resource blocks k can be stacked into a matrix:

$C_{F} = \begin{bmatrix}c_{l,0}^{T} \\\cdots \\c_{l,2L - 1}^{T}\end{bmatrix},$

which then can be expressed as:

$C_{F} = \begin{bmatrix}c_{l,0}^{T} \\\cdots \\c_{l,2L - 1}^{T}\end{bmatrix} = \begin{bmatrix}{a_{0}^{T}B^{T}} \\\cdots \\{a_{2L - 1}^{T}B^{T}}\end{bmatrix} = \begin{bmatrix}a_{0}^{T} \\\cdots \\a_{2L - 1}^{T}\end{bmatrix}B^{T} = {\widetilde{C}}_{F}B^{T}.$

The linear combination of beam basis vectors and beam coefficients canalso be expressed as a matrix product. This implies that the precoders(for all RBs) for a certain layer can be expressed as a matrix product:

W_(F) = W₁C_(F) = W₁C̃_(F)B^(T).

That is, a spatial linear transformation (from antenna domain to beamdomain) is applied from the left by multiplication of W₁ and from theright a frequency linear transformation by multiplication of B^(T). Theprecoders are then expressed more sparsely using a smaller coefficientmatrix C̃_(F) in this transformed domain.

FIG. 4 illustrates a matrix representation 400 of the Type II overheadreduction scheme described above, where examples of the dimensions ofthe matrix components of the precoder are illustrated.

There currently exist certain challenges. For example, Type II precoderschemes may lead to better MU-MIMO performance, but at the cost ofincreased CSI feedback overhead and UE precoder search complexity. It isan open problem of how an efficient Type II codebook that results ingood MU-MIMO performance, but low feedback overhead, should beconstructed, as well as how the CSI feedback should be derived by theUE.

SUMMARY

To address the foregoing problems with existing approaches, disclosed isa method performed by a wireless device. The method comprises obtaininga configuration for a sub-band CQI granularity and a sub-band PMIgranularity for the wireless device. The sub-band PMI granularitycorresponds to a first sub-band size and the sub-band CQI granularitycorresponds to a second sub-band size, and the first sub-band size issmaller than the second sub-band size. The method comprises determiningCSI feedback according to the configured sub-band CQI granularity andthe sub-band PMI granularity. The method comprises transmitting, to anetwork node, the determined CSI feedback.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity configuration maybe obtained from a subbandSize radio resource control (RRC) parameter ina CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be obtainedfrom a CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined. Incertain embodiments, a value range for the sub-band PMI granularity maybe aligned with a Precoding Resource block Group (PRG) size.

Also disclosed is a computer program, the computer program comprisinginstructions configured to perform the above-described method in awireless device.

Also disclosed is a computer program product, the computer programproduct comprising a non-transitory computer-readable storage medium,the non-transitory computer-readable storage medium comprising acomputer program comprising computer-executable instructions which, whenexecuted on a processor, are configured to perform the above-describedmethod in a wireless device.

Also disclosed is a wireless device. The wireless device comprises areceiver, a transmitter, and processing circuitry coupled to thereceiver and the transmitter. The processing circuitry is configured toobtain a configuration for a sub-band CQI granularity and a sub-band PMIgranularity for the wireless device. The sub-band PMI granularitycorresponds to a first sub-band size and the sub-band CQI granularitycorresponds to a second sub-band size, and the first sub-band size issmaller than the second sub-band size. The processing circuitry isconfigured to determine CSI feedback according to the configuredsub-band CQI granularity and the sub-band PMI granularity. Theprocessing circuitry is configured to transmit, to a network node, thedetermined CSI feedback.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the processing circuitry may be configured toobtain the sub-band CQI granularity configuration from a subbandSize RRCparameter in a CSI-ReportConfig.

In certain embodiments, the processing circuitry may be configured toobtain the sub-band PMI granularity from a CSI-ReportConfig using asubbandPMI-Size parameter.

In certain embodiments, the subbandPMI-Size parameter may have a valueof 1, 2, 4, or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

Also disclosed is a method performed by a network node. The methodcomprises determining a sub-band CQI granularity for a wireless device.The method comprises determining a sub-band PMI granularity for thewireless device. The method comprises configuring the wireless devicewith the sub-band CQI granularity and the sub-band PMI granularity,wherein the sub-band PMI granularity corresponds to a first sub-bandsize and the sub-band CQI granularity corresponds to a second sub-bandsize, and wherein the first sub-band size is smaller than the secondsub-band size.

In certain embodiments, the method may further comprise receiving CSIfeedback from the wireless device according to the configured sub-bandCQI granularity and the configured PMI granularity.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks. In certain embodiments, the sub-band PMIsize may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

Also disclosed is a computer program, the computer program comprisinginstructions configured to perform the above-described method in anetwork node.

Also disclosed is a computer program product, the computer programproduct comprising a non-transitory computer-readable storage medium,the non-transitory computer-readable storage medium comprising acomputer program comprising computer-executable instructions which, whenexecuted on a processor, are configured to perform the above-describedmethod in a network node.

Also disclosed is a network node. The network node comprises a receiver,a transmitter, and processing circuitry coupled to the receiver and thetransmitter. The processing circuitry is configured to determine asub-band CQI granularity for a wireless device. The processing circuitryis configured to determine a sub-band PMI granularity for the wirelessdevice. The processing circuitry is configured to configure the wirelessdevice with the sub-band CQI granularity and the sub-band PMIgranularity, wherein the sub-band PMI granularity corresponds to a firstsub-band size and the sub-band CQI granularity corresponds to a secondsub-band size, and wherein the first sub-band size is smaller than thesecond sub-band size.

In certain embodiments, the processing circuitry may be furtherconfigured to receive CSI feedback from the wireless device according tothe configured sub-band CQI granularity and the configured PMIgranularity.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

Also disclosed is a method performed by a network node. The methodcomprises receiving CSI feedback from a wireless device according to asub-band CQI granularity and a sub-band PMI granularity, wherein thesub-band PMI granularity corresponds to a first sub-band size and thesub-band CQI granularity corresponds to a second sub-band size, andwherein the first sub-band size is smaller than the second sub-bandsize.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

Also disclosed is a computer program, the computer program comprisinginstructions configured to perform the above-described method in anetwork node.

Also disclosed is a computer program product, the computer programproduct comprising a non-transitory computer-readable storage medium,the non-transitory computer-readable storage medium comprising acomputer program comprising computer-executable instructions which, whenexecuted on a processor, are configured to perform the above-describedmethod in a network node.

Also disclosed is a network node. The network node comprises a receiver,a transmitter, and processing circuitry coupled to the receiver and thetransmitter. The processing circuitry is configured to receive CSIfeedback from a wireless device according to a sub-band CQI granularityand a sub-band PMI granularity, wherein the sub-band PMI granularitycorresponds to a first sub-band size and the sub-band CQI granularitycorresponds to a second sub-band size, and wherein the first sub-bandsize is smaller than the second sub-band size.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

Certain embodiments of the present disclosure may provide one or moretechnical advantages. As one example, certain embodiments mayadvantageously provide improved PMI granularity without causingunnecessarily large CQI overhead. As another example, certainembodiments may advantageously enable the sub-band size for PMI and CQIto be independently configured. Other advantages may be readily apparentto one having skill in the art. Certain embodiments may have none, some,or all of the recited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed embodiments and theirfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates a transmission structure of precoded spatialmultiplexing mode in NR, in accordance with certain embodiments;

FIG. 2 illustrates a two-dimensional antenna array of cross-polarizedantenna elements, in accordance with certain embodiments;

FIG. 3 illustrates an example of resource element allocation for a12-port CSI-RS in NR, in accordance with certain embodiments;

FIG. 4 illustrates a matrix representation of the Type II overheadreduction scheme, in accordance with certain embodiments;

FIG. 5 illustrates an example wireless network, in accordance withcertain embodiments;

FIG. 6 is a flowchart illustrating an example of a method performed by awireless device, in accordance with certain embodiments;

FIG. 7 is a block diagram illustrating an example of a virtualapparatus, in accordance with certain embodiments;

FIG. 8 is a flowchart illustrating an example of a method performed by anetwork node, in accordance with certain embodiments;

FIG. 9 is a flowchart illustrating an example of a method performed by anetwork node, in accordance with certain embodiments;

FIG. 10 is a block diagram illustrating an example of a virtualapparatus, in accordance with certain embodiments.

FIG. 11 illustrates an example user equipment, in accordance withcertain embodiments;

FIG. 12 illustrates an example virtualization environment, in accordancewith certain embodiments;

FIG. 13 illustrates an example telecommunication network connected viaan intermediate network to a host computer, in accordance with certainembodiments;

FIG. 14 illustrates an example host computer communicating via a basestation with a user equipment over a partially wireless connection, inaccordance with certain embodiments;

FIG. 15 is a flowchart illustrating an example method implemented in acommunication system, in accordance certain embodiments;

FIG. 16 is a flowchart illustrating a second example method implementedin a communication system, in accordance with certain embodiments;

FIG. 17 is a flowchart illustrating a third method implemented in acommunication system, in accordance with certain embodiments; and

FIG. 18 is a flowchart illustrating a fourth method implemented in acommunication system, in accordance with certain embodiments.

DETAILED DESCRIPTION

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thefollowing description.

As described above, with MU-MIMO, two or more users in the same cell canbe co-scheduled on the same time-frequency resource. Because one centralpart of MU-MIMO is obtaining accurate CSI that enables nullformingbetween co-scheduled users, support has been added in LTE Rel-14 and NRRel-15 for codebooks that provide more detailed CSI than the traditionalsingle DFT-beam precoders. These codebooks are referred to as AdvancedCSI (in LTE) or Type II codebooks (in NR). Although Type II precoderschemes may lead to better MU-MIMO performance, Type II precoder schemesare problematic due to increased CSI feedback overhead and UE precodersearch complexity. Thus, there is a need for an efficient Type IIcodebook that results in good MU-MIMO performance and low feedbackoverhead as well as an improved method for deriving the CSI feedback bythe UE.

Certain aspects of the present disclosure and the embodiments describedherein may provide solutions to these or other challenges.

According to one example embodiment, a method performed by a wirelessdevice (e.g., a UE) is disclosed. The wireless device obtains aconfiguration for a sub-band CQI granularity and a sub-band PMIgranularity for the wireless device. The sub-band PMI granularity maycorrespond to a first sub-band size and the sub-band CQI granularity maycorrespond to a second sub-band size. The first sub-band size may besmaller than the second sub-band size. This may advantageously enablethe sub-band size for PMI and CQI to be independently configured. Thewireless device determines CSI feedback according to the configuredsub-band CQI granularity and the sub-band PMI granularity. The wirelessdevice transmits, to a network node, the determined CSI feedback.

According to other example embodiments, a corresponding wireless device,computer program, and computer program product are also disclosed.

According to another example embodiment, a method performed by a networknode is disclosed. The network node determines a sub-band CQIgranularity for a wireless device. The network node determines asub-band PMI granularity for the wireless device. The network nodeconfigures the wireless device with the sub-band CQI granularity and thesub-band PMI granularity. The sub-band PMI granularity may correspond toa first sub-band size and the sub-band CQI granularity may correspond toa second sub-band size. The first sub-band size may be smaller than thesecond sub-band size.

According to other example embodiments, a corresponding network node,computer program, and computer program product are also disclosed.

According to another example embodiment, a method performed by a networknode is disclosed. The network node receives CSI feedback from awireless device according to a sub-band CQI granularity and a sub-bandPMI granularity. The sub-band PMI granularity may correspond to a firstsub-band size and the sub-band CQI granularity may correspond to asecond sub-band size. The first sub-band size may be smaller than thesecond sub-band size.

According to other example embodiments, a corresponding network node,computer program, and computer program product are also disclosed.

Some of the embodiments contemplated herein will now be described morefully with reference to the accompanying drawings. Other embodiments,however, are contained within the scope of the subject matter disclosedherein, the disclosed subject matter should not be construed as limitedto only the embodiments set forth herein; rather, these embodiments areprovided by way of example to convey the scope of the subject matter tothose skilled in the art.

FIG. 5 illustrates a wireless network in accordance with someembodiments. Although the subject matter described herein may beimplemented in any appropriate type of system using any suitablecomponents, the embodiments disclosed herein are described in relationto a wireless network, such as the example wireless network illustratedin FIG. 5 . For simplicity, the wireless network of FIG. 5 only depictsnetwork 506, network nodes 560 and 560 b, and wireless devices 510, 510b, and 510 c. In practice, a wireless network may further include anyadditional elements suitable to support communication between wirelessdevices or between a wireless device and another communication device,such as a landline telephone, a service provider, or any other networknode or end device. Of the illustrated components, network node 560 andwireless device 510 are depicted with additional detail. The wirelessnetwork may provide communication and other types of services to one ormore wireless devices to facilitate the wireless devices’ access toand/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless localarea network (WLAN) standards, such as the IEEE 802.11 standards; and/orany other appropriate wireless communication standard, such as theWorldwide Interoperability for Microwave Access (WiMax), Bluetooth,Z-Wave and/or ZigBee standards.

Network 506 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 560 and wireless device 510 comprise various componentsdescribed in more detail below. These components work together in orderto provide network node and/or wireless device functionality, such asproviding wireless connections in a wireless network. In differentembodiments, the wireless network may comprise any number of wired orwireless networks, network nodes, base stations, controllers, wirelessdevices, relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs(eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based onthe amount of coverage they provide (or, stated differently, theirtransmit power level) and may then also be referred to as femto basestations, pico base stations, micro base stations, or macro basestations. A base station may be a relay node or a relay donor nodecontrolling a relay. A network node may also include one or more (orall) parts of a distributed radio base station such as centralizeddigital units and/or remote radio units (RRUs), sometimes referred to asRemote Radio Heads (RRHs). Such remote radio units may or may not beintegrated with an antenna as an antenna integrated radio. Parts of adistributed radio base station may also be referred to as nodes in adistributed antenna system (DAS). Yet further examples of network nodesinclude multi-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 5 , network node 560 includes processing circuitry 570, devicereadable medium 580, interface 590, auxiliary equipment 584, powersource 586, power circuitry 587, and antenna 562. Although network node560 illustrated in the example wireless network of FIG. 5 may representa device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 560 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 580 may comprise multiple separate hard drives aswell as multiple RAM modules).

Similarly, network node 560 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 560comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeB’s.In such a scenario, each unique NodeB and RNC pair, may in someinstances be considered a single separate network node. In someembodiments, network node 560 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate device readable medium 580 for thedifferent RATs) and some components may be reused (e.g., the sameantenna 562 may be shared by the RATs). Network node 560 may alsoinclude multiple sets of the various illustrated components fordifferent wireless technologies integrated into network node 560, suchas, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wirelesstechnologies. These wireless technologies may be integrated into thesame or different chip or set of chips and other components withinnetwork node 560.

Processing circuitry 570 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 570 may include processing informationobtained by processing circuitry 570 by, for example, converting theobtained information into other information, comparing the obtainedinformation or converted information to information stored in thenetwork node, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Processing circuitry 570 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 560 components, such as device readable medium 580, network node560 functionality. For example, processing circuitry 570 may executeinstructions stored in device readable medium 580 or in memory withinprocessing circuitry 570. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 570 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 570 may include one or more ofradio frequency (RF) transceiver circuitry 572 and baseband processingcircuitry 574. In some embodiments, radio frequency (RF) transceivercircuitry 572 and baseband processing circuitry 574 may be on separatechips (or sets of chips), boards, or units, such as radio units anddigital units. In alternative embodiments, part or all of RF transceivercircuitry 572 and baseband processing circuitry 574 may be on the samechip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 570executing instructions stored on device readable medium 580 or memorywithin processing circuitry 570. In alternative embodiments, some or allof the functionality may be provided by processing circuitry 570 withoutexecuting instructions stored on a separate or discrete device readablemedium, such as in a hard-wired manner. In any of those embodiments,whether executing instructions stored on a device readable storagemedium or not, processing circuitry 570 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 570 alone or to other components ofnetwork node 560, but are enjoyed by network node 560 as a whole, and/orby end users and the wireless network generally.

Device readable medium 580 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 570. Device readable medium 580 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 570 and, utilized by network node 560. Devicereadable medium 580 may be used to store any calculations made byprocessing circuitry 570 and/or any data received via interface 590. Insome embodiments, processing circuitry 570 and device readable medium580 may be considered to be integrated.

Interface 590 is used in the wired or wireless communication ofsignalling and/or data between network node 560, network 506, and/orwireless devices 510. As illustrated, interface 590 comprisesport(s)/terminal(s) 594 to send and receive data, for example to andfrom network 506 over a wired connection. Interface 590 also includesradio front end circuitry 592 that may be coupled to, or in certainembodiments a part of, antenna 562. Radio front end circuitry 592comprises filters 598 and amplifiers 596. Radio front end circuitry 592may be connected to antenna 562 and processing circuitry 570. Radiofront end circuitry may be configured to condition signals communicatedbetween antenna 562 and processing circuitry 570. Radio front endcircuitry 592 may receive digital data that is to be sent out to othernetwork nodes or wireless devices via a wireless connection. Radio frontend circuitry 592 may convert the digital data into a radio signalhaving the appropriate channel and bandwidth parameters using acombination of filters 598 and/or amplifiers 596. The radio signal maythen be transmitted via antenna 562. Similarly, when receiving data,antenna 562 may collect radio signals which are then converted intodigital data by radio front end circuitry 592. The digital data may bepassed to processing circuitry 570. In other embodiments, the interfacemay comprise different components and/or different combinations ofcomponents.

In certain alternative embodiments, network node 560 may not includeseparate radio front end circuitry 592, instead, processing circuitry570 may comprise radio front end circuitry and may be connected toantenna 562 without separate radio front end circuitry 592. Similarly,in some embodiments, all or some of RF transceiver circuitry 572 may beconsidered a part of interface 590. In still other embodiments,interface 590 may include one or more ports or terminals 594, radiofront end circuitry 592, and RF transceiver circuitry 572, as part of aradio unit (not shown), and interface 590 may communicate with basebandprocessing circuitry 574, which is part of a digital unit (not shown).

Antenna 562 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 562 may becoupled to radio front end circuitry 590 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 562 may comprise one or more omni-directional,sector or panel antennas operable to transmit/receive radio signalsbetween, for example, 2 GHz and 66 GHz. An omni-directional antenna maybe used to transmit/receive radio signals in any direction, a sectorantenna may be used to transmit/receive radio signals from deviceswithin a particular area, and a panel antenna may be a line of sightantenna used to transmit/receive radio signals in a relatively straightline. In some instances, the use of more than one antenna may bereferred to as MIMO. In certain embodiments, antenna 562 may be separatefrom network node 560 and may be connectable to network node 560 throughan interface or port. Certain embodiments of the present disclosure maybe used with two-dimensional antenna arrays.

Antenna 562, interface 590, and/or processing circuitry 570 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 562, interface 590, and/or processing circuitry 570 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 587 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node 560with power for performing the functionality described herein. Powercircuitry 587 may receive power from power source 586. Power source 586and/or power circuitry 587 may be configured to provide power to thevarious components of network node 560 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 586 may either be included in,or external to, power circuitry 587 and/or network node 560. Forexample, network node 560 may be connectable to an external power source(e.g., an electricity outlet) via an input circuitry or interface suchas an electrical cable, whereby the external power source supplies powerto power circuitry 587. As a further example, power source 586 maycomprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 587. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 560 may include additionalcomponents beyond those shown in FIG. 5 that may be responsible forproviding certain aspects of the network node’s functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 560 may include user interface equipment to allow input ofinformation into network node 560 and to allow output of informationfrom network node 560. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node560.

As used herein, wireless device refers to a device capable, configured,arranged and/or operable to communicate wirelessly with network nodesand/or other wireless devices. Unless otherwise noted, the term wirelessdevice may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a wireless device may be configured totransmit and/or receive information without direct human interaction.For instance, a wireless device may be designed to transmit informationto a network on a predetermined schedule, when triggered by an internalor external event, or in response to requests from the network. Examplesof a wireless device include, but are not limited to, a smart phone, amobile phone, a cell phone, a voice over IP (VoIP) phone, a wirelesslocal loop phone, a desktop computer, a personal digital assistant(PDA), a wireless cameras, a gaming console or device, a music storagedevice, a playback appliance, a wearable terminal device, a wirelessendpoint, a mobile station, a tablet, a laptop, a laptop-embeddedequipment (LEE), a laptop-mounted equipment (LME), a smart device, awireless customer-premise equipment (CPE), a vehicle-mounted wirelessterminal device, etc.. A wireless device may support device-to-device(D2D) communication, for example by implementing a 3GPP standard forsidelink communication, vehicle-to-vehicle (V2V),vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may inthis case be referred to as a D2D communication device. As yet anotherspecific example, in an Internet of Things (IoT) scenario, a wirelessdevice may represent a machine or other device that performs monitoringand/or measurements, and transmits the results of such monitoring and/ormeasurements to another wireless device and/or a network node. Thewireless device may in this case be a machine-to-machine (M2M) device,which may in a 3GPP context be referred to as an MTC device. As oneparticular example, the wireless device may be a UE implementing the3GPP narrow band internet of things (NB-IoT) standard. Particularexamples of such machines or devices are sensors, metering devices suchas power meters, industrial machinery, or home or personal appliances(e.g. refrigerators, televisions, etc.) personal wearables (e.g.,watches, fitness trackers, etc.). In other scenarios, a wireless devicemay represent a vehicle or other equipment that is capable of monitoringand/or reporting on its operational status or other functions associatedwith its operation. A wireless device as described above may representthe endpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a wireless device asdescribed above may be mobile, in which case it may also be referred toas a mobile device or a mobile terminal.

As illustrated, wireless device 510 includes antenna 511, interface 514,processing circuitry 520, device readable medium 530, user interfaceequipment 532, auxiliary equipment 534, power source 536 and powercircuitry 537. Wireless device 510 may include multiple sets of one ormore of the illustrated components for different wireless technologiessupported by wireless device 510, such as, for example, GSM, WCDMA, LTE,NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention afew. These wireless technologies may be integrated into the same ordifferent chips or set of chips as other components within wirelessdevice 510.

Antenna 511 may include one or more antennas or antenna arrays,configured to send and/or receive wireless signals, and is connected tointerface 514. In certain alternative embodiments, antenna 511 may beseparate from wireless device 510 and be connectable to wireless device510 through an interface or port. Antenna 511, interface 514, and/orprocessing circuitry 520 may be configured to perform any receiving ortransmitting operations described herein as being performed by awireless device. Any information, data and/or signals may be receivedfrom a network node and/or another wireless device. In some embodiments,radio front end circuitry and/or antenna 511 may be considered aninterface. Certain embodiments of the present disclosure may be usedwith two-dimensional antenna arrays.

As illustrated, interface 514 comprises radio front end circuitry 512and antenna 511. Radio front end circuitry 512 comprise one or morefilters 518 and amplifiers 516. Radio front end circuitry 514 isconnected to antenna 511 and processing circuitry 520, and is configuredto condition signals communicated between antenna 511 and processingcircuitry 520. Radio front end circuitry 512 may be coupled to or a partof antenna 511. In some embodiments, wireless device 510 may not includeseparate radio front end circuitry 512; rather, processing circuitry 520may comprise radio front end circuitry and may be connected to antenna511. Similarly, in some embodiments, some or all of RF transceivercircuitry 522 may be considered a part of interface 514. Radio front endcircuitry 512 may receive digital data that is to be sent out to othernetwork nodes or wireless devices via a wireless connection. Radio frontend circuitry 512 may convert the digital data into a radio signalhaving the appropriate channel and bandwidth parameters using acombination of filters 518 and/or amplifiers 516. The radio signal maythen be transmitted via antenna 511. Similarly, when receiving data,antenna 511 may collect radio signals which are then converted intodigital data by radio front end circuitry 512. The digital data may bepassed to processing circuitry 520. In other embodiments, the interfacemay comprise different components and/or different combinations ofcomponents.

Processing circuitry 520 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other wirelessdevice 510 components, such as device readable medium 530, wirelessdevice 510 functionality. Such functionality may include providing anyof the various wireless features or benefits discussed herein. Forexample, processing circuitry 520 may execute instructions stored indevice readable medium 530 or in memory within processing circuitry 520to provide the functionality disclosed herein.

As illustrated, processing circuitry 520 includes one or more of RFtransceiver circuitry 522, baseband processing circuitry 524, andapplication processing circuitry 526. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry520 of wireless device 510 may comprise a SOC. In some embodiments, RFtransceiver circuitry 522, baseband processing circuitry 524, andapplication processing circuitry 526 may be on separate chips or sets ofchips. In alternative embodiments, part or all of baseband processingcircuitry 524 and application processing circuitry 526 may be combinedinto one chip or set of chips, and RF transceiver circuitry 522 may beon a separate chip or set of chips. In still alternative embodiments,part or all of RF transceiver circuitry 522 and baseband processingcircuitry 524 may be on the same chip or set of chips, and applicationprocessing circuitry 526 may be on a separate chip or set of chips. Inyet other alternative embodiments, part or all of RF transceivercircuitry 522, baseband processing circuitry 524, and applicationprocessing circuitry 526 may be combined in the same chip or set ofchips. In some embodiments, RF transceiver circuitry 522 may be a partof interface 514. RF transceiver circuitry 522 may condition RF signalsfor processing circuitry 520.

In certain embodiments, some or all of the functionality describedherein as being performed by a wireless device may be provided byprocessing circuitry 520 executing instructions stored on devicereadable medium 530, which in certain embodiments may be acomputer-readable storage medium. In alternative embodiments, some orall of the functionality may be provided by processing circuitry 520without executing instructions stored on a separate or discrete devicereadable storage medium, such as in a hard-wired manner. In any of thoseparticular embodiments, whether executing instructions stored on adevice readable storage medium or not, processing circuitry 520 can beconfigured to perform the described functionality. The benefits providedby such functionality are not limited to processing circuitry 520 aloneor to other components of wireless device 510, but are enjoyed bywireless device 510 as a whole, and/or by end users and the wirelessnetwork generally.

Processing circuitry 520 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a wireless device. Theseoperations, as performed by processing circuitry 520, may includeprocessing information obtained by processing circuitry 520 by, forexample, converting the obtained information into other information,comparing the obtained information or converted information toinformation stored by wireless device 510, and/or performing one or moreoperations based on the obtained information or converted information,and as a result of said processing making a determination.

Device readable medium 530 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 520. Device readable medium 530 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 520. In someembodiments, processing circuitry 520 and device readable medium 530 maybe considered to be integrated.

User interface equipment 532 may provide components that allow for ahuman user to interact with wireless device 510. Such interaction may beof many forms, such as visual, audial, tactile, etc. User interfaceequipment 532 may be operable to produce output to the user and to allowthe user to provide input to wireless device 510. The type ofinteraction may vary depending on the type of user interface equipment532 installed in wireless device 510. For example, if wireless device510 is a smart phone, the interaction may be via a touch screen; ifwireless device 510 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 532 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 532 is configured to allow input of information into wirelessdevice 510, and is connected to processing circuitry 520 to allowprocessing circuitry 520 to process the input information. Userinterface equipment 532 may include, for example, a microphone, aproximity or other sensor, keys/buttons, a touch display, one or morecameras, a USB port, or other input circuitry. User interface equipment532 is also configured to allow output of information from wirelessdevice 510, and to allow processing circuitry 520 to output informationfrom wireless device 510. User interface equipment 532 may include, forexample, a speaker, a display, vibrating circuitry, a USB port, aheadphone interface, or other output circuitry. Using one or more inputand output interfaces, devices, and circuits, of user interfaceequipment 532, wireless device 510 may communicate with end users and/orthe wireless network, and allow them to benefit from the functionalitydescribed herein.

Auxiliary equipment 534 is operable to provide more specificfunctionality which may not be generally performed by wireless devices.This may comprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 534 may vary depending on the embodiment and/or scenario.

Power source 536 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. Wireless device 510 may further comprise powercircuitry 537 for delivering power from power source 536 to the variousparts of wireless device 510 which need power from power source 536 tocarry out any functionality described or indicated herein. Powercircuitry 537 may in certain embodiments comprise power managementcircuitry. Power circuitry 537 may additionally or alternatively beoperable to receive power from an external power source; in which casewireless device 510 may be connectable to the external power source(such as an electricity outlet) via input circuitry or an interface suchas an electrical power cable. Power circuitry 537 may also in certainembodiments be operable to deliver power from an external power sourceto power source 536. This may be, for example, for the charging of powersource 536. Power circuitry 537 may perform any formatting, converting,or other modification to the power from power source 536 to make thepower suitable for the respective components of wireless device 510 towhich power is supplied.

In existing CSI reporting mechanisms, when frequency-selective CSIreporting is configured, a sub-band size is typically either configuredor pre-defined in the specification. A wireless device, such as wirelessdevice 510, reports a separate PMI and CQI for each such sub-band. ThePMI may in turn consist of a wideband PMI part, which is selected oncefor all sub-bands (such as the i₁ index described in 3GPP TS 38.214v15.3.0, corresponding to a W₁ matrix) and a per-sub-band part (such asthe i₂ index in 3GPP TS 38.214 corresponding to a W₂ matrix), where thetotal precoder for the sub-band n is determined based on the combinationof i₁ and i₂, such as:

W(n) = W₁(i₁)W₂(i₂(n)).

Similarly, the CQI may have a wideband component and a sub-bandcomponent, which combined yields the resulting reported CQI for thatsub-band. In any regard, in existing approaches there is a one-to-onemapping between the sub-band CQI and the sub-band PMI for a certainsub-band, and the sub-band size and position is thus the same for boththe CQI and PMI. The sub-band PMI and sub-band CQI for all the sub-bandsn = 0, ..., N_(SB) are then typically reported in consecutive order inthe Uplink Control Information (UCI), as for example given in the belowtable of 3GPP TS 38.212 v15.3.0. Essentially, the sub-band PMI and CQIpayload linearly scales with the number of sub-bands.

TABLE 63212-5 Mapping order of CSI fields of one CSI report, CSI part 2subband CSI report #n Part 2 subband Subband differential CQI for thesecond TB of all even subbands with increasing order of subband number,as in Tables 6.3.1.1.2-3/4/5, if cqi-Formatlndicator-subbandCQl and ifreported PMI subband information fields ^(X) ₂ of all even subbands withincreasing order of subband number, from left to right as in Tables6.3.1.1.2-1/2 or 6.3.2.1.2-1/2, or codebook index for 2 antenna portsaccording to Subclause 5.2.2.2.1 in [6, TS38.214] of all even subbandswith increasing order of subband number, ifpmi-FormatIndicator=subbandPMI and if reported Subband differential CQIfor the second TB of all odd subbands with increasing order of subbandnumber, as in Tables 6.3.1.1.2-3/4/5, if cqi-FormatIndicator=subbandCQIand if reported PMI subband information fields X₂ of all odd subbandswith increasing order of subband number, from left to right as in Tables6.3.1.1.2-1/2 or 6.3.2.1.2-1/2, or codebook index for 2 antenna portsaccording to Subclause 5.2.2.2.1 in [6, TS38.214] of all odd subbandswith increasing order of subband number, if pmi-FormatIndicator =subbandPMI and if reported

This implies that in existing approaches, the sub-band PMI and sub-bandCQI have the same granularity, and network node 560 (e.g., a gNB), uponreceiving the CSI report, may determine a precoder from the PMI thatcorresponds to the same number of PRBs as the corresponding CQI. Indeed,in existing approaches the sub-band CQI is calculated by wireless device510 conditioned on the reported PMI for that sub-band.

For the Type II CSI enhancement considered for NR Rel-16, as part of thePMI, the coefficients for each beam c_(l,i) are parameterized in thefrequency-domain as the linear combination of a set of basis vectors,described by the matrix B and a number of linear combining coefficientsc_(l,i) = Ba_(i). Thus, the overhead of the PMI feedback does notlinearly depend on the PMI sub-band granularity anymore (i.e., thelength of the vector c_(l,i) and thus the dimension of the basis vectorsin the matrix B), but instead on the number of linear combiningcoefficients (i.e., the number of columns in B). Accordingly, thegranularity of the PMI may be increased so that wireless device 510feeds back a PMI report that can be used by network node 560 todetermine a precoder with much higher frequency-granularity, withoutsubstantially increasing the PMI overhead. The PMI sub-band granularitymay therefore be a subcarrier granularity, PRB granularity or generallyan integer number of PRBs. This can enable a significant performanceincrease as a precoder that more precisely matches thefrequency-selective channel results in better beamforming gain as wellas better interference suppression capability when MU-MIMO is performed.

If an existing approach were used, however, where a sub-band PMI has acoupled sub-band CQI, the sub-band CQI overhead would increasedramatically as the sub-band CQI payload still scales linearly with thenumber of sub-bands. To illustrate, consider the maximum bandwidth of NRof 275 PRBs. If each PRB were to correspond to a sub-band, the sub-bandCQI payload would be 2*275 = 550 bits. This is not feasible.Furthermore, the granularity of sub-band CQI is not as directly linkedto performance as that of sub-band PMI. Sub-band CQI is only useful asan aid for frequency-selective scheduling. Even if the precodergranularity is very fine, the scheduling granularity may be much largersuch that having too fine sub-band CQI granularity gives little benefit.

The present disclosure contemplates various embodiments for defining thesub-band PMI granularity and the sub-band CQI granularity separately. Incertain embodiments, network node 560 determines a sub-band CQIgranularity for a wireless device, such as wireless device 510. Networknode 560 also determines a sub-band PMI granularity for wireless device510. The sub-band PMI granularity may correspond to a first sub-bandsize and the sub-band CQI granularity may correspond to a secondsub-band size. The first sub-band size may be smaller than the secondsub-band size. This may advantageously enable the sub-band size for PMIand CQI to be independently configured.

Network node 560 configures wireless device 510 with the sub-band CQIgranularity and the sub-band PMI granularity. In certain embodiments,network node 560 may transmit a configuration for the sub-band CQIgranularity and the sub-band PMI granularity to wireless device 510. Asdescribed in more detail below, the sub-band CQI granularity may beconfigured using a subbandSize RRC parameter in CSI-ReportConfig. And,as described in more detail below, the sub-band PMI granularity may beconfigured per CSI-ReportConfig using a subbandPMI-Size parameter.

In certain embodiments, wireless device 510 obtains a configuration forthe sub-band CQI granularity and the sub-band PMI granularity forwireless device 510. As described above, the sub-band PMI granularitymay correspond to a first sub-band size and the sub-band CQI granularitymay correspond to a second sub-band size. The first sub-band size may besmaller than the second sub-band size. In certain embodiments, thesecond sub-band size may be an integer multiple of the first sub-bandsize.

The sub-band CQI granularity (i.e., sub-band size for CQI) may bedefined using the RRC parameter subbandSize in CSI-ReportConfig.Accordingly, in certain embodiments wireless device 510 may obtain thesub-band CQI granularity configuration from a subbandSize RRC parameterin the CSI-ReportConfig. Additionally or alternatively, a new RRCparameter to configure the sub-band CQI granularity may be introduced.Thus, in certain embodiments wireless device 510 may obtain the sub-bandCQI granularity configuration from the new RRC parameter.

The sub-band PMI granularity (i.e, sub-band size for PMI) may beconfigured per CSI-ReportConfig using a separate parameter, for instancesubbandPMI-Size. Accordingly, in certain embodiments wireless device 510may obtain the sub-band PMI granularity from a CSI-ReportConfig using asubbandPMI-Size parameter. In certain embodiments, the subbandPMI-Sizeparameter may have a value of 1, 2, 4, or 8 PRBs.

In certain embodiments, the sub-band PMI granularity may be upperbounded by the sub-band CQI granularity. In other embodiments, thesub-band PMI granularity may be subbandSize/X where subbandSize is thesub-band CQI granularity and X is an integer. Or, to put it differently,there may be a constraint that the sub-band CQI granularity is aninteger multiple of the sub-band PMI granularity.

In certain embodiments, the sub-band PMI size may be fixed in thespecification, for instance to 1, 2 or 4 PRBs. Thus, in certainembodiments the sub-band PMI size may be pre-defined.

Wireless device 510 determines CSI feedback according to the configuredsub-band CQI granularity and the sub-band PMI granularity. Wirelessdevice 510 transmits, to network node 560, the determined CSI feedback.In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. The PMI may indicate a preferred precoder matrix foreach frequency sub-band of the first sub-band size. Each of theplurality of CQI may correspond to the second sub-band size.

In certain embodiments, network node 560 receives the CSI feedback fromwireless device 510 according to the sub-band CQI granularity and thesub-band PMI granularity. As described above, the sub-band PMIgranularity may correspond to a first sub-band size and the sub-band CQIgranularity may correspond to a second sub-band size, and the firstsub-band size may be smaller than the second sub-band size.

In some cases, there may be little benefit of receiving more granularPMI than can be used for scheduling according to the configuredPrecoding Resource block Group (PRG) size for wireless device 510 (whichdictates that the precoding of demodulation reference signals (DMRS)antenna ports across a PRG is the same). The PRG size may be coupledwith the sub-band PMI granularity. In certain embodiments, the valuerange of the parameters that configures the sub-band PMI granularity isaligned with that which configures the PRG size (i.e., 2 or 4 PRBs inNR). In an alternative embodiment, the sub-band PMI granularity may bedetermined based on the configured PRG size such that they are alwaysaligned. Thus, in certain embodiments a value range for the sub-band PMIgranularity may be aligned with a PRG size.

In certain embodiments, the configuration of independent sub-band PMIand CQI granularities may be used when certain CSI feedback modes areused. In certain embodiments, it may depend on the RRC parameterreportQuantity in CSI-ReportConfig, such that, for instance, theconfiguration of independent sub-band PMI and CQI granularities may onlybe used when the Rel-16 enhanced Type II CSI report is configured.

In certain embodiments, one sub-band CQI quantity could be determinedconditioned on multiple selected sub-band PMIs (where the “sub-band”PMIs typically would be jointly determined using the aforementionedfrequency parametrization approach as considered by Type II overheadreduction in NR Rel-16).

FIG. 6 is a flowchart illustrating an example of a method 600 performedby a wireless device, in accordance with certain embodiments. Method 600begins at step 601, where the wireless device obtains a configurationfor a sub-band CQI granularity and a sub-band PMI granularity for thewireless device. The sub-band PMI granularity corresponds to a firstsub-band size and the sub-band CQI granularity corresponds to a secondsub-band size. The first sub-band size is smaller than the secondsub-band size.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the sub-band CQI granularity configuration maybe obtained from a subbandSize RRC parameter in a CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be obtainedfrom a CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined. Incertain embodiments, a value range for the sub-band PMI granularity maybe aligned with a Precoding Resource block Group (PRG) size.

At step 602, the wireless device determines CSI feedback according tothe configured sub-band CQI granularity and the sub-band PMIgranularity.

At step 603, the wireless device transmits, to a network node, thedetermined CSI feedback.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

FIG. 7 is a block diagram illustrating an example of a virtual appartus,in accordance with certain embodiments. More particularly, FIG. 7illustrates a schematic block diagram of an apparatus 700 in a wirelessnetwork (for example, the wireless network shown in FIG. 5 ). Theapparatus may be implemented in a wireless device (e.g., wireless device510 shown in FIG. 5 ). Apparatus 700 is operable to carry out theexample method described with reference to FIG. 6 and possibly any otherprocesses or methods disclosed herein. It is also to be understood thatthe method of FIG. 6 is not necessarily carried out solely by apparatus700. At least some operations of the method can be performed by one ormore other entities.

Virtual Apparatus 700 may comprise processing circuitry, which mayinclude one or more microprocessor or microcontrollers, as well as otherdigital hardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory, cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein, in several embodiments. In someimplementations, the processing circuitry may be used to cause receivingunit 702, determining unit 704, communication unit 706, and any othersuitable units of apparatus 700 to perform corresponding functionsaccording one or more embodiments of the present disclosure.

In certain embodiments, apparatus 700 may be a UE. As illustrated inFIG. 7 , apparatus 700 includes receiving unit 702, determining unit704, and communication unit 706. Receiving unit 702 may be configured toperform the receiving functions of apparatus 700. For example, receivingunit 702 may be configured to obtain a configuration for a sub-band CQIgranularity and a sub-band PMI granularity for the wireless device. Thesub-band PMI granularity may correspond to a first sub-band size and thesub-band CQI granularity may correspond to a second sub-band size. Thefirst sub-band size may be smaller than the second sub-band size. Incertain embodiments, the second sub-band size may be an integer multipleof the first sub-band size.

In certain embodiments, receiving unit 702 may be configured to obtainthe sub-band CQI granularity configuration from a subbandSize RRCparameter in a CSI-ReportConfig. In certain embodiments, receiving unit702 may be configured to obtain the sub-band PMI granularity from aCSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 PRBs. In certain embodiments, the sub-band PMI size may bepre-defined. In certain embodiments, a value range for the sub-band PMIgranularity may be aligned with a PRG size.

Receiving unit 702 may receive any suitable information (e.g., fromanother wireless device or a network node). Receiving unit 702 mayinclude a receiver and/or a transceiver, such as RF transceivercircuitry 522 described above in relation to FIG. 5 . Receiving unit 702may include circuitry configured to receive messages and/or signals(wireless or wired). In particular embodiments, receiving unit 702 maycommunicate received messages and/or signals to determining unit 704and/or any other suitable unit of apparatus 700. The functions ofreceiving unit 702 may, in certain embodiments, be performed in one ormore distinct units.

Determining unit 704 may perform the processing functions of apparatus700. For example, determining unit 704 may be configured to obtain aconfiguration for a sub-band CQI granularity and a sub-band PMIgranularity for the wireless device. In certain embodiments, determiningunit 704 may be configured to obtain the sub-band CQI granularityconfiguration from a subbandSize RRC parameter in a CSI-ReportConfig. Incertain embodiments, determining unit 704 may be configured to obtainthe sub-band PMI granularity from a CSI-ReportConfig using asubbandPMI-Size parameter. In certain embodiments, determining unit 704may be configured to obtain the configuration for the sub-band CQIgranularity and the sub-band PMI granularity from receiving unit 702.

As another example, determining unit 704 may be configured to determineCSI feedback according to the configured sub-band CQI granularity andthe sub-band PMI granularity. In certain embodiments, the CSI feedbackmay comprise a PMI and a plurality of CQI. In certain embodiments, thePMI may indicate a preferred precoder matrix for each frequency sub-bandof the first sub-band size. In certain embodiments, each of theplurality of CQI may correspond to the second sub-band size.

As another example, determining unit 704 may be configured to provideuser data.

Determining unit 704 may include or be included in one or moreprocessors, such as processing circuitry 520 described above in relationto FIG. 5 . Determining unit 704 may include analog and/or digitalcircuitry configured to perform any of the functions of determining unit704 and/or processing circuitry 520 described above. The functions ofdetermining unit 704 may, in certain embodiments, be performed in one ormore distinct units.

Communication unit 706 may be configured to perform the transmissionfunctions of apparatus 700. For example, communication unit 706 may beconfigured to transmit, to a network node, the determined CSI feedback.As another example, communication unit 706 may be configured to forwardthe user data to a host computer via a transmission to the base station.

Communication unit 706 may transmit messages (e.g., to a wireless deviceand/or another network node). Communication unit 706 may include atransmitter and/or a transceiver, such as RF transceiver circuitry 522described above in relation to FIG. 5 . Communication unit 706 mayinclude circuitry configured to transmit messages and/or signals (e.g.,through wireless or wired means). In particular embodiments,communication unit 706 may receive messages and/or signals fortransmission from determining unit 704 or any other unit of apparatus700. The functions of communication unit 704 may, in certainembodiments, be performed in one or more distinct units.

FIG. 8 is a flowchart illustrating an example of a method 800 performedby a network node, in accordance with certain embodiments. Method 800begins at step 801, where the network node determines a sub-band CQIgranularity for a wireless device.

At step 802, the network node determines a sub-band PMI granularity forthe wireless device.

At step 803, the network node configures the wireless device with thesub-band CQI granularity and the sub-band PMI granularity, wherein thesub-band PMI granularity corresponds to a first sub-band size and thesub-band CQI granularity corresponds to a second sub-band size, andwherein the first sub-band size is smaller than the second sub-bandsize.

In certain embodiments, the method may further comprise receiving CSIfeedback from the wireless device according to the configured sub-bandCQI granularity and the configured PMI granularity.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQIcorresponds to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks. In certain embodiments, the sub-band PMIsize may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

FIG. 9 is a flowchart illustrating an example of a method 900 performedby a network node, in accordance with certain embodiments. Method 900begins at step 901, where the network node receives CSI feedback from awireless device according to a sub-band CQI granularity and a sub-bandPMI granularity, wherein the sub-band PMI granularity corresponds to afirst sub-band size and the sub-band CQI granularity corresponds to asecond sub-band size, and wherein the first sub-band size is smallerthan the second sub-band size.

In certain embodiments, the second sub-band size may be an integermultiple of the first sub-band size.

In certain embodiments, the CSI feedback may comprise a PMI and aplurality of CQI. In certain embodiments, the PMI may indicate apreferred precoder matrix for each frequency sub-band of the firstsub-band size. In certain embodiments, each of the plurality of CQI maycorrespond to the second sub-band size.

In certain embodiments, the sub-band CQI granularity may be configuredusing a subbandSize RRC parameter in CSI-ReportConfig.

In certain embodiments, the sub-band PMI granularity may be configuredper CSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks.

In certain embodiments, the sub-band PMI size may be pre-defined.

In certain embodiments, a value range for the sub-band PMI granularitymay be aligned with a PRG size.

FIG. 10 is a block diagram illustrating an example of a virtualapparatus, in accordance with certain embodiments. More particularly,FIG. 10 illustrates a schematic block diagram of an apparatus 1000 in awireless network (for example, the wireless network shown in FIG. 5 ).The apparatus may be implemented in a network node (e.g., network node560 shown in FIG. 5 ). Apparatus 1000 is operable to carry out theexample methods described above with reference to FIGS. 8 and 9 andpossibly any other processes or methods disclosed herein. It is also tobe understood that the methods of FIGS. 8 and 9 are not necessarilycarried out solely by apparatus 1000. At least some operations of themethod can be performed by one or more other entities.

Virtual Apparatus 1000 may comprise processing circuitry, which mayinclude one or more microprocessor or microcontrollers, as well as otherdigital hardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory, cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein, in several embodiments. In someimplementations, the processing circuitry may be used to cause receivingunit 1002, determining unit 1004, communication unit 1006, and any othersuitable units of apparatus 1000 to perform corresponding functionsaccording one or more embodiments of the present disclosure.

In certain embodiments, apparatus 1000 may be an eNB or a gNB. Asillustrated in FIG. 10 , apparatus 1000 includes receiving unit 1002,determining unit 1004, and communication unit 1006. Receiving unit 1002may be configured to perform the receiving functions of apparatus 1000.For example, receiving unit 1002 may be configured to receive CSIfeedback from the wireless device according to the configured sub-bandCQI granularity and the configured PMI granularity. As another example,receiving unit 1002 may be configured to receive CSI feedback from awireless device according to a sub-band CQI granularity and a sub-bandPMI granularity, wherein the sub-band PMI granularity corresponds to afirst sub-band size and the sub-band CQI granularity corresponds to asecond sub-band size, and wherein the first sub-band size is smallerthan the second sub-band size. In certain embodiments, the secondsub-band size may be an integer multiple of the first sub-band size. Incertain embodiments, the CSI feedback may comprise a PMI and a pluralityof CQI. In certain embodiments, the PMI may indicate a preferredprecoder matrix for each frequency sub-band of the first sub-band size.In certain embodiments, each of the plurality of CQI may correspond tothe second sub-band size.

As another example, receiving unit 1002 may be configured to obtain userdata.

Receiving unit 1002 may receive any suitable information (e.g., from awireless device or another network node). Receiving unit 1002 mayinclude a receiver and/or a transceiver, such as RF transceivercircuitry 572 described above in relation to FIG. 5 . Receiving unit1002 may include circuitry configured to receive messages and/or signals(wireless or wired). In particular embodiments, receiving unit 1002 maycommunicate received messages and/or signals to determining unit 1004and/or any other suitable unit of apparatus 1000. The functions ofreceiving unit 1002 may, in certain embodiments, be performed in one ormore distinct units.

Determining unit 1004 may perform the processing functions of apparatus1000. For example, determining unit 1004 may be configured to determinea sub-band CQI granularity for a wireless device. As another example,determining unit 1004 may be configured to determine a sub-band PMIgranularity for the wireless device. In certain embodiments, a valuerange for the sub-band PMI granularity may be aligned with a PRG size.

As still another example, determining unit 1004 may be configured toconfigure the wireless device with the sub-band CQI granularity and thesub-band PMI granularity, wherein the sub-band PMI granularitycorresponds to a first sub-band size and the sub-band CQI granularitycorresponds to a second sub-band size, and wherein the first sub-bandsize is smaller than the second sub-band size. In certain embodiments,determining unit 1004 may be configured to configure the sub-band PMIgranularity independent of the sub-band CQI granularity. In certainembodiments, determining unit 1004 may be configured to configure thesub-band CQI granularity using a subbandSize RRC parameter inCSI-ReportConfig. In certain embodiments, determining unit 1004 may beconfigured to configure the sub-band PMI granularity perCSI-ReportConfig using a subbandPMI-Size parameter. In certainembodiments, the subbandPMI-Size parameter may have a value of 1, 2, 4,or 8 physical resource blocks. In certain embodiments, the sub-band PMIsize may be pre-defined. As another example, determining unit 1004 maybe configured to obtain user data.

Determining unit 1004 may include or be included in one or moreprocessors, such as processing circuitry 570 described above in relationto FIG. 5 . Determining unit 1004 may include analog and/or digitalcircuitry configured to perform any of the functions of determining unit1004 and/or processing circuitry 570 described above. The functions ofdetermining unit 1004 may, in certain embodiments, be performed in oneor more distinct units.

Communication unit 1006 may be configured to perform the transmissionfunctions of apparatus 1000. For example, communication unit 1006 may beconfigured to configure the wireless device with the sub-band CQIgranularity and the sub-band PMI granularity. In certain embodiments,communication unit 1006 may be configured to transmit a CSI-ReportConfigto wireless device. In certain embodiments, communication unit 1006 maybe configured to configure the sub-band CQI granularity using asubbandSize RRC parameter in CSI-ReportConfig. In certain embodiments,communication unit 1006 may be configured to configure the sub-band PMIgranularity per CSI-ReportConfig using a subbandPMI-Size parameter. Asanother example, communication unit 1006 may be configured to forwardthe user data to a host computer or a wireless device.

Communication unit 1006 may transmit messages (e.g., to a wirelessdevice and/or another network node). Communication unit 1006 may includea transmitter and/or a transceiver, such as RF transceiver circuitry 572described above in relation to FIG. 5 . Communication unit 1006 mayinclude circuitry configured to transmit messages and/or signals (e.g.,through wireless or wired means). In particular embodiments,communication unit 1006 may receive messages and/or signals fortransmission from determining unit 1004 or any other unit of apparatus1000. The functions of communication unit 1004 may, in certainembodiments, be performed in one or more distinct units.

The term unit may have conventional meaning in the field of electronics,electrical devices and/or electronic devices and may include, forexample, electrical and/or electronic circuitry, devices, modules,processors, memories, logic solid state and/or discrete devices,computer programs or instructions for carrying out respective tasks,procedures, computations, outputs, and/or displaying functions, and soon, as such as those that are described herein.

In some embodiments a computer program, computer program product orcomputer readable storage medium comprises instructions which whenexecuted on a computer perform any of the embodiments disclosed herein.In further examples the instructions are carried on a signal or carrierand which are executable on a computer wherein when executed perform anyof the embodiments disclosed herein.

FIG. 11 illustrates an example user equipment, in accordance withcertain embodiments. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser (e.g., a smart sprinkler controller). Alternatively, a UE mayrepresent a device that is not intended for sale to, or operation by, anend user but which may be associated with or operated for the benefit ofa user (e.g., a smart power meter). UE 1100 may be any UE identified bythe 3^(rd) Generation Partnership Project (3GPP), including a NB-IoT UE,a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.UE 1100, as illustrated in FIG. 11 , is one example of a wireless deviceconfigured for communication in accordance with one or morecommunication standards promulgated by the 3^(rd) Generation PartnershipProject (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. Asmentioned previously, the term wireless device and UE may be usedinterchangeable. Accordingly, although FIG. 11 is a UE, the componentsdiscussed herein are equally applicable to a wireless device, andvice-versa.

In FIG. 11 , UE 1100 includes processing circuitry 1101 that isoperatively coupled to input/output interface 1105, radio frequency (RF)interface 1109, network connection interface 1111, memory 1115 includingrandom access memory (RAM) 1117, read-only memory (ROM) 1119, andstorage medium 1121 or the like, communication subsystem 1131, powersource 1133, and/or any other component, or any combination thereof.Storage medium 1121 includes operating system 1123, application program1125, and data 1127. In other embodiments, storage medium 1121 mayinclude other similar types of information. Certain UEs may utilize allof the components shown in FIG. 11 , or only a subset of the components.The level of integration between the components may vary from one UE toanother UE. Further, certain UEs may contain multiple instances of acomponent, such as multiple processors, memories, transceivers,transmitters, receivers, etc.

In FIG. 11 , processing circuitry 1101 may be configured to processcomputer instructions and data. Processing circuitry 1101 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 1101 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 1105 may beconfigured to provide a communication interface to an input device,output device, or input and output device. UE 1100 may be configured touse an output device via input/output interface 1105. An output devicemay use the same type of interface port as an input device. For example,a USB port may be used to provide input to and output from UE 1100. Theoutput device may be a speaker, a sound card, a video card, a display, amonitor, a printer, an actuator, an emitter, a smartcard, another outputdevice, or any combination thereof. UE 1100 may be configured to use aninput device via input/output interface 1105 to allow a user to captureinformation into UE 1100. The input device may include a touch-sensitiveor presence-sensitive display, a camera (e.g., a digital camera, adigital video camera, a web camera, etc.), a microphone, a sensor, amouse, a trackball, a directional pad, a trackpad, a scroll wheel, asmartcard, and the like. The presence-sensitive display may include acapacitive or resistive touch sensor to sense input from a user. Asensor may be, for instance, an accelerometer, a gyroscope, a tiltsensor, a force sensor, a magnetometer, an optical sensor, a proximitysensor, another like sensor, or any combination thereof. For example,the input device may be an accelerometer, a magnetometer, a digitalcamera, a microphone, and an optical sensor.

In FIG. 11 , RF interface 1109 may be configured to provide acommunication interface to RF components such as a transmitter, areceiver, and an antenna. Network connection interface 1111 may beconfigured to provide a communication interface to network 1143 a.Network 1143 a may encompass wired and/or wireless networks such as alocal-area network (LAN), a wide-area network (WAN), a computer network,a wireless network, a telecommunications network, another like networkor any combination thereof. For example, network 1143 a may comprise aWi-Fi network. Network connection interface 1111 may be configured toinclude a receiver and a transmitter interface used to communicate withone or more other devices over a communication network according to oneor more communication protocols, such as Ethernet, TCP/IP, SONET, ATM,or the like. Network connection interface 1111 may implement receiverand transmitter functionality appropriate to the communication networklinks (e.g., optical, electrical, and the like). The transmitter andreceiver functions may share circuit components, software or firmware,or alternatively may be implemented separately.

RAM 1117 may be configured to interface via bus 1102 to processingcircuitry 1101 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 1119 maybe configured to provide computer instructions or data to processingcircuitry 1101. For example, ROM 1119 may be configured to storeinvariant low-level system code or data for basic system functions suchas basic input and output (I/O), startup, or reception of keystrokesfrom a keyboard that are stored in a non-volatile memory. Storage medium1121 may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 1121 may be configured toinclude operating system 1123, application program 1125 such as a webbrowser application, a widget or gadget engine or another application,and data file 1127. Storage medium 1121 may store, for use by UE 1100,any of a variety of various operating systems or combinations ofoperating systems.

Storage medium 1121 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 1121 may allow UE 1100 to access computer-executableinstructions, application programs or the like, stored on transitory ornon-transitory memory media, to off-load data, or to upload data. Anarticle of manufacture, such as one utilizing a communication system maybe tangibly embodied in storage medium 1121, which may comprise a devicereadable medium.

In FIG. 11 , processing circuitry 1101 may be configured to communicatewith network 1143 b using communication subsystem 1131. Network 1143 aand network 1143 b may be the same network or networks or differentnetwork or networks. Communication subsystem 1131 may be configured toinclude one or more transceivers used to communicate with network 1143b. For example, communication subsystem 1131 may be configured toinclude one or more transceivers used to communicate with one or moreremote transceivers of another device capable of wireless communicationsuch as another wireless device, UE, or base station of a radio accessnetwork (RAN) according to one or more communication protocols, such asIEEE 802.11, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Eachtransceiver may include transmitter 1133 and/or receiver 1135 toimplement transmitter or receiver functionality, respectively,appropriate to the RAN links (e.g., frequency allocations and the like).Further, transmitter 1133 and receiver 1135 of each transceiver mayshare circuit components, software or firmware, or alternatively may beimplemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 1131 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 1131 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 1143 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network1143 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 1113 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 1100.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 1100 or partitioned acrossmultiple components of UE 1100. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem1131 may be configured to include any of the components describedherein. Further, processing circuitry 1101 may be configured tocommunicate with any of such components over bus 1102. In anotherexample, any of such components may be represented by programinstructions stored in memory that when executed by processing circuitry1101 perform the corresponding functions described herein. In anotherexample, the functionality of any of such components may be partitionedbetween processing circuitry 1101 and communication subsystem 1131. Inanother example, the non-computationally intensive functions of any ofsuch components may be implemented in software or firmware and thecomputationally intensive functions may be implemented in hardware.

FIG. 12 illustrates an example virtualization environment, in accordancewith certain embodiments. More particularly, FIG. 12 is a schematicblock diagram illustrating a virtualization environment 1200 in whichfunctions implemented by some embodiments may be virtualized. In thepresent context, virtualizing means creating virtual versions ofapparatuses or devices which may include virtualizing hardwareplatforms, storage devices and networking resources. As used herein,virtualization can be applied to a node (e.g., a virtualized basestation or a virtualized radio access node) or to a device (e.g., a UE,a wireless device or any other type of communication device) orcomponents thereof and relates to an implementation in which at least aportion of the functionality is implemented as one or more virtualcomponents (e.g., via one or more applications, components, functions,virtual machines or containers executing on one or more physicalprocessing nodes in one or more networks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 1200 hosted byone or more of hardware nodes 1230. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 1220 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 1220 are runin virtualization environment 1200 which provides hardware 1230comprising processing circuitry 1260 and memory 1290. Memory 1290contains instructions 1295 executable by processing circuitry 1260whereby application 1220 is operative to provide one or more of thefeatures, benefits, and/or functions disclosed herein.

Virtualization environment 1200, comprises general-purpose orspecial-purpose network hardware devices 1230 comprising a set of one ormore processors or processing circuitry 1260, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 1290-1 which may benon-persistent memory for temporarily storing instructions 1295 orsoftware executed by processing circuitry 1260. Each hardware device maycomprise one or more network interface controllers (NICs) 1270, alsoknown as network interface cards, which include physical networkinterface 1280. Each hardware device may also include non-transitory,persistent, machine-readable storage media 1290-2 having stored thereinsoftware 1295 and/or instructions executable by processing circuitry1260. Software 1295 may include any type of software including softwarefor instantiating one or more virtualization layers 1250 (also referredto as hypervisors), software to execute virtual machines 1240 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 1240, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 1250 or hypervisor. Differentembodiments of the instance of virtual appliance 1220 may be implementedon one or more of virtual machines 1240, and the implementations may bemade in different ways.

During operation, processing circuitry 1260 executes software 1295 toinstantiate the hypervisor or virtualization layer 1250, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 1250 may present a virtual operating platform thatappears like networking hardware to virtual machine 1240.

As shown in FIG. 12 , hardware 1230 may be a standalone network nodewith generic or specific components. Hardware 1230 may comprise antenna12225 and may implement some functions via virtualization.Alternatively, hardware 1230 may be part of a larger cluster of hardware(e.g. such as in a data center or customer premise equipment (CPE))where many hardware nodes work together and are managed via managementand orchestration (MANO) 12100, which, among others, oversees lifecyclemanagement of applications 1220.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 1240 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 1240, and that part of hardware 1230 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 1240, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 1240 on top of hardware networking infrastructure1230 and corresponds to application 1220 in FIG. 12 .

In some embodiments, one or more radio units 12200 that each include oneor more transmitters 12220 and one or more receivers 12210 may becoupled to one or more antennas 12225. Radio units 12200 may communicatedirectly with hardware nodes 1230 via one or more appropriate networkinterfaces and may be used in combination with the virtual components toprovide a virtual node with radio capabilities, such as a radio accessnode or a base station.

In some embodiments, some signalling can be effected with the use ofcontrol system 12230 which may alternatively be used for communicationbetween the hardware nodes 1230 and radio units 12200.

FIG. 13 illustrates an example telecommunication network connected viaan intermediate network to a host computer, in accordance with certainembodiments. With reference to FIG. 13 , in accordance with anembodiment, a communication system includes telecommunication network1310, such as a 3GPP-type cellular network, which comprises accessnetwork 1311, such as a radio access network, and core network 1314.Access network 1311 comprises a plurality of base stations 1312 a, 1312b, 1312 c, such as NBs, eNBs, gNBs or other types of wireless accesspoints, each defining a corresponding coverage area 1313 a, 1313 b, 1313c. Each base station 1312 a, 1312 b, 1312 c is connectable to corenetwork 1314 over a wired or wireless connection 1315. A first UE 1391located in coverage area 1313 c is configured to wirelessly connect to,or be paged by, the corresponding base station 1312 c. A second UE 1392in coverage area 1313 a is wirelessly connectable to the correspondingbase station 1312 a. While a plurality of UEs 1391, 1392 are illustratedin this example, the disclosed embodiments are equally applicable to asituation where a sole UE is in the coverage area or where a sole UE isconnecting to the corresponding base station 1312.

Telecommunication network 1310 is itself connected to host computer1330, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 1330 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1321 and 1322 between telecommunication network 1310 andhost computer 1330 may extend directly from core network 1314 to hostcomputer 1330 or may go via an optional intermediate network 1320.Intermediate network 1320 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1320,if any, may be a backbone network or the Internet; in particular,intermediate network 1320 may comprise two or more sub-networks (notshown).

The communication system of FIG. 13 as a whole enables connectivitybetween the connected UEs 1391, 1392 and host computer 1330. Theconnectivity may be described as an over-the-top (OTT) connection 1350.Host computer 1330 and the connected UEs 1391, 1392 are configured tocommunicate data and/or signaling via OTT connection 1350, using accessnetwork 1311, core network 1314, any intermediate network 1320 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1350 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1350 passes areunaware of routing of uplink and downlink communications. For example,base station 1312 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1330 to be forwarded (e.g., handed over) to a connected UE1391. Similarly, base station 1312 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1391towards the host computer 1330.

FIG. 14 illustrates an example of a host computer communicating via abase station with a user equipment over a partially wireless connection,in accordance with certain embodiments.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 14 . In communicationsystem 1400, host computer 1410 comprises hardware 1415 includingcommunication interface 1416 configured to set up and maintain a wiredor wireless connection with an interface of a different communicationdevice of communication system 1400. Host computer 1410 furthercomprises processing circuitry 1418, which may have storage and/orprocessing capabilities. In particular, processing circuitry 1418 maycomprise one or more programmable processors, application-specificintegrated circuits, field programmable gate arrays or combinations ofthese (not shown) adapted to execute instructions. Host computer 1410further comprises software 1411, which is stored in or accessible byhost computer 1410 and executable by processing circuitry 1418. Software1411 includes host application 1412. Host application 1412 may beoperable to provide a service to a remote user, such as UE 1430connecting via OTT connection 1450 terminating at UE 1430 and hostcomputer 1410. In providing the service to the remote user, hostapplication 1412 may provide user data which is transmitted using OTTconnection 1450.

Communication system 1400 further includes base station 1420 provided ina telecommunication system and comprising hardware 1425 enabling it tocommunicate with host computer 1410 and with UE 1430. Hardware 1425 mayinclude communication interface 1426 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 1400, as well as radiointerface 1427 for setting up and maintaining at least wirelessconnection 1470 with UE 1430 located in a coverage area (not shown inFIG. 14 ) served by base station 1420. Communication interface 1426 maybe configured to facilitate connection 1460 to host computer 1410.Connection 1460 may be direct or it may pass through a core network (notshown in FIG. 14 ) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 1425 of base station 1420 further includesprocessing circuitry 1428, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 1420 further has software 1421 storedinternally or accessible via an external connection.

Communication system 1400 further includes UE 1430 already referred to.Its hardware 1435 may include radio interface 1437 configured to set upand maintain wireless connection 1470 with a base station serving acoverage area in which UE 1430 is currently located. Hardware 1435 of UE1430 further includes processing circuitry 1438, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 1430 further comprisessoftware 1431, which is stored in or accessible by UE 1430 andexecutable by processing circuitry 1438. Software 1431 includes clientapplication 1432. Client application 1432 may be operable to provide aservice to a human or non-human user via UE 1430, with the support ofhost computer 1410. In host computer 1410, an executing host application1412 may communicate with the executing client application 1432 via OTTconnection 1450 terminating at UE 1430 and host computer 1410. Inproviding the service to the user, client application 1432 may receiverequest data from host application 1412 and provide user data inresponse to the request data. OTT connection 1450 may transfer both therequest data and the user data. Client application 1432 may interactwith the user to generate the user data that it provides.

It is noted that host computer 1410, base station 1420 and UE 1430illustrated in FIG. 14 may be similar or identical to host computer1330, one of base stations 1312 a, 1312 b, 1312 c and one of UEs 1391,1392 of FIG. 13 , respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 14 and independently, thesurrounding network topology may be that of FIG. 13 .

In FIG. 14 , OTT connection 1450 has been drawn abstractly to illustratethe communication between host computer 1410 and UE 1430 via basestation 1420, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 1430 or from the service provider operating host computer1410, or both. While OTT connection 1450 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 1470 between UE 1430 and base station 1420 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 1430 using OTT connection1450, in which wireless connection 1470 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the signalingoverhead.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 1450 between hostcomputer 1410 and UE 1430, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 1450 may be implemented in software 1411and hardware 1415 of host computer 1410 or in software 1431 and hardware1435 of UE 1430, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 1450 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 1411, 1431 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 1450 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 1420, and it may be unknownor imperceptible to base station 1420. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 1410′s measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 1411 and 1431 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 1450 while it monitors propagation times, errors etc.

FIG. 15 is a flowchart illustrating an example method implemented in acommunication system, in accordance with certain embodiments. Moreparticularly, FIG. 15 illustrates an example method implemented in acommunication system including a host computer, a base station and auser equipment. The communication system includes a host computer, abase station and a UE which may be those described with reference toFIGS. 13 and 14 . For simplicity of the present disclosure, only drawingreferences to FIG. 15 will be included in this section. In step 1510,the host computer provides user data. In substep 1511 (which may beoptional) of step 1510, the host computer provides the user data byexecuting a host application. In step 1520, the host computer initiatesa transmission carrying the user data to the UE. In step 1530 (which maybe optional), the base station transmits to the UE the user data whichwas carried in the transmission that the host computer initiated, inaccordance with the teachings of the embodiments described throughoutthis disclosure. In step 1540 (which may also be optional), the UEexecutes a client application associated with the host applicationexecuted by the host computer.

FIG. 16 is a flowchart illustrating a second example method implementedin a communication system, in accordance with certain embodiments. Moreparticularly, FIG. 16 illustrates an example method implemented in acommunication system including a host computer, a base station and auser equipment. The communication system includes a host computer, abase station and a UE which may be those described with reference toFIGS. 13 and 14 . For simplicity of the present disclosure, only drawingreferences to FIG. 16 will be included in this section. In step 1610 ofthe method, the host computer provides user data. In an optional substep(not shown) the host computer provides the user data by executing a hostapplication. In step 1620, the host computer initiates a transmissioncarrying the user data to the UE. The transmission may pass via the basestation, in accordance with the teachings of the embodiments describedthroughout this disclosure. In step 1630 (which may be optional), the UEreceives the user data carried in the transmission.

FIG. 17 is a flowchart illustrating a third method implemented in acommunication system, in accordance with certain embodiments. Moreparticularly, FIG. 17 illustrates an example method implemented in acommunication system including a host computer, a base station and auser equipment. The communication system includes a host computer, abase station and a UE which may be those described with reference toFIGS. 13 and 14 . For simplicity of the present disclosure, only drawingreferences to FIG. 17 will be included in this section. In step 1710(which may be optional), the UE receives input data provided by the hostcomputer. Additionally or alternatively, in step 1720, the UE providesuser data. In substep 1721 (which may be optional) of step 1720, the UEprovides the user data by executing a client application. In substep1711 (which may be optional) of step 1710, the UE executes a clientapplication which provides the user data in reaction to the receivedinput data provided by the host computer. In providing the user data,the executed client application may further consider user input receivedfrom the user. Regardless of the specific manner in which the user datawas provided, the UE initiates, in substep 1730 (which may be optional),transmission of the user data to the host computer. In step 1740 of themethod, the host computer receives the user data transmitted from theUE, in accordance with the teachings of the embodiments describedthroughout this disclosure.

FIG. 18 is a flowchart illustrating a fourth method implemented in acommunication system, in accordance with certain embodiments. Moreparticularly, FIG. 18 illustrates an example method implemented in acommunication system including a host computer, a base station and auser equipment. The communication system includes a host computer, abase station and a UE which may be those described with reference toFIGS. 13 and 14 . For simplicity of the present disclosure, only drawingreferences to FIG. 18 will be included in this section. In step 1810(which may be optional), in accordance with the teachings of theembodiments described throughout this disclosure, the base stationreceives user data from the UE. In step 1820 (which may be optional),the base station initiates transmission of the received user data to thehost computer. In step 1830 (which may be optional), the host computerreceives the user data carried in the transmission initiated by the basestation.

Certain example embodiments contemplated by the present disclosure aredescribed below. Note that the enumerated embodiments below are forpurposes of example only, and the present disclosure is not limited tothe example embodiments enumerated below.

Group A Embodiments

1. A method performed by a wireless device, comprising:

-   obtaining a configuration for a subband channel quality indicator    (CQI) granularity and a subband precoding matrix indicator (PMI)    granularity for the wireless device;-   determining channel state information (CSI) feedback according to    the configured subband CQI granularity and the subband PMI    granularity; and-   transmitting, to a network node, the determined CSI feedback.

2. The method of embodiment 1, wherein the subband PMI granularity isconfigured independent of the subband CQI granularity.

3. The method of any of embodiments 1-2, wherein the CSI feedbackcomprises a PMI and a plurality of CQI.

4. The method of embodiment 3, wherein the PMI indicates a preferredprecoder matrix for each frequency subband of a first subband size.

5. The method of embodiment 4, wherein each of the plurality of CQIcorresponds to a second subband size.

6. The method of embodiment 5, wherein the first subband size is smallerthan the second subband size.

7. The method of embodiment 5, wherein the first subband size is largerthan the second subband size.

8. The method of any of embodiments 1-7, wherein the subband CQIgranularity configuration is obtained from a subbandSize radio resourcecontrol parameter in a CSI-ReportConfig.

9. The method of any of embodiments 1-8, wherein the subband PMIgranularity is obtained from a CSI-ReportConfig using a subbandPMI-Sizeparameter.

10. The method of embodiment 9, wherein the subbandPMI-Size parameterhas a value of 1, 2, 4, or 8 physical resource blocks.

11. The method of any of embodiments 1-10, wherein the subband PMIgranularity is upper bounded by the subband CQI granularity.

12. The method of any of embodiments 1-10, wherein the value of thesubband PMI granularity is constrained such that the subband CQIgranularity is an integer multiple of the subband PMI granularity.

13. The method of any of embodiments 1-12, wherein the subband PMI sizeis pre-defined.

14. The method of any of embodiments 1-12, wherein a value range for thesubband PMI granularity is aligned with a Physical Resource block Group(PRG) size.

15. The method of any of embodiments 1-14, further comprising:

-   providing user data; and-   forwarding the user data to a host computer via the transmission to    the base station.

Group B Embodiments

16. A method performed by a network node, comprising:

-   determining a subband channel quality indicator (CQI) granularity    for a wireless device;-   determining a subband precoding matrix indicator (PMI) granularity    for the wireless device; and-   configuring the wireless device with the subband CQI granularity and    the subband PMI granularity.

17. The method of embodiment 16, wherein the subband PMI granularity isconfigured independent of the subband CQI granularity.

18. The method of any of embodiments 16-17, further comprising receivingchannel state information (CSI) feedback from the wireless deviceaccording to the configured subband CQI granularity and the configuredPMI granularity.

19. The method of embodiment 18, wherein the CSI feedback comprises aPMI and a plurality of CQI.

20. The method of embodiment 19, wherein the PMI indicates a preferredprecoder matrix for each frequency subband of a first subband size.

21. The method of any of embodiments 19-20, wherein each of theplurality of CQI corresponds to a second subband size.

22. The method of embodiment 21, wherein the first subband size issmaller than the second subband size.

23. The method of embodiment 21, wherein the first subband size islarger than the second subband size.

24. The method of any of embodiments 16-23, wherein the subband CQIgranularity is configured using a subbandSize radio resource controlparameter in CSI-ReportConfig.

25. The method of any of embodiments 16-24, wherein the subband PMIgranularity is configured per CSI-ReportConfig using a subbandPMI-Sizeparameter.

26. The method of embodiment 25, wherein the subbandPMI-Size parameterhas a value of 1, 2, 4, or 8 physical resource blocks.

27. The method of any of embodiments 16-26, wherein the subband PMIgranularity is upper bounded by the subband CQI granularity.

28. The method of any of embodiments 16-26, wherein the value of thesubband PMI granularity is constrained such that the subband CQIgranularity is an integer multiple of the subband PMI granularity.

29. The method of any of embodiments 16-28, wherein the subband PMI sizeis pre-defined.

30. The method of any of embodiments 16-28, wherein a value range forthe subband PMI granularity is aligned with a Physical Resource blockGroup (PRG) size.

31. The method of any of embodiments 16-30, further comprising:

-   obtaining user data; and-   forwarding the user data to a host computer or a wireless device.

Group C Embodiments

32. A wireless device, the wireless device comprising:

-   processing circuitry configured to perform any of the steps of any    of the Group A embodiments; and-   power supply circuitry configured to supply power to the wireless    device.

33. A network node, the network node comprising:

-   processing circuitry configured to perform any of the steps of any    of the Group B embodiments;-   power supply circuitry configured to supply power to the network    node.

34. A user equipment (UE), the UE comprising:

-   an antenna configured to send and receive wireless signals;-   radio front-end circuitry connected to the antenna and to processing    circuitry, and configured to condition signals communicated between    the antenna and the processing circuitry;-   the processing circuitry being configured to perform any of the    steps of any of the Group A embodiments;-   an input interface connected to the processing circuitry and    configured to allow input of information into the UE to be processed    by the processing circuitry;-   an output interface connected to the processing circuitry and    configured to output information from the UE that has been processed    by the processing circuitry; and-   a battery connected to the processing circuitry and configured to    supply power to the UE.

35. A computer program, the computer program comprising instructionswhich when executed on a computer perform any of the steps of any of theGroup A embodiments.

36. A computer program product comprising a computer program, thecomputer program comprising instructions which when executed on acomputer perform any of the steps of any of the Group A embodiments.

37. A non-transitory computer-readable storage medium or carriercomprising a computer program, the computer program comprisinginstructions which when executed on a computer perform any of the stepsof any of the Group A embodiments.

38. A computer program, the computer program comprising instructionswhich when executed on a computer perform any of the steps of any of theGroup B embodiments.

39. A computer program product comprising a computer program, thecomputer program comprising instructions which when executed on acomputer perform any of the steps of any of the Group B embodiments.

40. A non-transitory computer-readable storage medium or carriercomprising a computer program, the computer program comprisinginstructions which when executed on a computer perform any of the stepsof any of the Group B embodiments.

41. A communication system including a host computer comprising:

-   processing circuitry configured to provide user data; and-   a communication interface configured to forward the user data to a    cellular network for transmission to a user equipment (UE),-   wherein the cellular network comprises a network node having a radio    interface and processing circuitry, the network node’s processing    circuitry configured to perform any of the steps of any of the Group    B embodiments.

42. The communication system of the pervious embodiment furtherincluding the network node.

43. The communication system of the previous 2 embodiments, furtherincluding the UE, wherein the UE is configured to communicate with thenetwork node.

44. The communication system of the previous 3 embodiments, wherein:

-   the processing circuitry of the host computer is configured to    execute a host application, thereby providing the user data; and-   the UE comprises processing circuitry configured to execute a client    application associated with the host application.

45. A method implemented in a communication system including a hostcomputer, a network node and a user equipment (UE), the methodcomprising:

-   at the host computer, providing user data; and-   at the host computer, initiating a transmission carrying the user    data to the UE via a cellular network comprising the network node,    wherein the network node performs any of the steps of any of the    Group B embodiments.

46. The method of the previous embodiment, further comprising, at thenetwork node, transmitting the user data.

47. The method of the previous 2 embodiments, wherein the user data isprovided at the host computer by executing a host application, themethod further comprising, at the UE, executing a client applicationassociated with the host application.

48. A user equipment (UE) configured to communicate with a network node,the UE comprising a radio interface and processing circuitry configuredto performs the of the previous 3 embodiments.

49. A communication system including a host computer comprising:

-   processing circuitry configured to provide user data; and-   a communication interface configured to forward user data to a    cellular network for transmission to a user equipment (UE),-   wherein the UE comprises a radio interface and processing circuitry,    the UE’s components configured to perform any of the steps of any of    the Group A embodiments.

50. The communication system of the previous embodiment, wherein thecellular network further includes a network node configured tocommunicate with the UE.

51. The communication system of the previous 2 embodiments, wherein:

-   the processing circuitry of the host computer is configured to    execute a host application, thereby providing the user data; and-   the UE’s processing circuitry is configured to execute a client    application associated with the host application.

52. A method implemented in a communication system including a hostcomputer, a network node and a user equipment (UE), the methodcomprising:

-   at the host computer, providing user data; and-   at the host computer, initiating a transmission carrying the user    data to the UE via a cellular network comprising the network node,    wherein the UE performs any of the steps of any of the Group A    embodiments.

53. The method of the previous embodiment, further comprising at the UE,receiving the user data from the network node.

54. A communication system including a host computer comprising:

-   communication interface configured to receive user data originating    from a transmission from a user equipment (UE) to a network node,-   wherein the UE comprises a radio interface and processing circuitry,    the UE’s processing circuitry configured to perform any of the steps    of any of the Group A embodiments.

55. The communication system of the previous embodiment, furtherincluding the UE.

56. The communication system of the previous 2 embodiments, furtherincluding the network node, wherein the network node comprises a radiointerface configured to communicate with the UE and a communicationinterface configured to forward to the host computer the user datacarried by a transmission from the UE to the network node.

57. The communication system of the previous 3 embodiments, wherein:

-   the processing circuitry of the host computer is configured to    execute a host application; and-   the UE’s processing circuitry is configured to execute a client    application associated with the host application, thereby providing    the user data.

58. The communication system of the previous 4 embodiments, wherein:

-   the processing circuitry of the host computer is configured to    execute a host application, thereby providing request data; and-   the UE’s processing circuitry is configured to execute a client    application associated with the host application, thereby providing    the user data in response to the request data.

59. A method implemented in a communication system including a hostcomputer, a network node and a user equipment (UE), the methodcomprising:

-   at the host computer, receiving user data transmitted to the network    node from the UE, wherein the UE performs any of the steps of any of    the Group A embodiments.

60. The method of the previous embodiment, further comprising, at theUE, providing the user data to the network node.

61. The method of the previous 2 embodiments, further comprising:

-   at the UE, executing a client application, thereby providing the    user data to be transmitted; and-   at the host computer, executing a host application associated with    the client application.

62. The method of the previous 3 embodiments, further comprising:

-   at the UE, executing a client application; and-   at the UE, receiving input data to the client application, the input    data being provided at the host computer by executing a host    application associated with the client application,-   wherein the user data to be transmitted is provided by the client    application in response to the input data.

63. A communication system including a host computer comprising acommunication interface configured to receive user data originating froma transmission from a user equipment (UE) to a network node, wherein thenetwork node comprises a radio interface and processing circuitry, thenetwork node’s processing circuitry configured to perform any of thesteps of any of the Group B embodiments.

64. The communication system of the previous embodiment furtherincluding the network node.

65. The communication system of the previous 2 embodiments, furtherincluding the UE, wherein the UE is configured to communicate with thenetwork node.

66. The communication system of the previous 3 embodiments, wherein:

-   the processing circuitry of the host computer is configured to    execute a host application;-   the UE is configured to execute a client application associated with    the host application, thereby providing the user data to be received    by the host computer.

67. A method implemented in a communication system including a hostcomputer, a network node and a user equipment (UE), the methodcomprising:

-   at the host computer, receiving, from the network node, user data    originating from a transmission which the network node has received    from the UE, wherein the UE performs any of the steps of any of the    Group A embodiments.

68. The method of the previous embodiment, further comprising at thenetwork node, receiving the user data from the UE.

69. The method of the previous 2 embodiments, further comprising at thenetwork node, initiating a transmission of the received user data to thehost computer.

Modifications, additions, or omissions may be made to the systems andapparatuses described herein without departing from the scope of thedisclosure. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components.Additionally, operations of the systems and apparatuses may be performedusing any suitable logic comprising software, hardware, and/or otherlogic. As used in this document, “each” refers to each member of a setor each member of a subset of a set.

Modifications, additions, or omissions may be made to the methodsdescribed herein without departing from the scope of the disclosure. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions, and alterations are possible without departing from thespirit and scope of this disclosure, as defined by the following claims.

At least some of the following abbreviations may be used in thisdisclosure. If there is an inconsistency between abbreviations,preference should be given to how it is used above. If listed multipletimes below, the first listing should be preferred over any subsequentlisting(s).

1x RTT CDMA2000 1x Radio Transmission Technology 3GPP 3rd GenerationPartnership Project 5G 5th Generation ABS Almost Blank Subframe ARQAutomatic Repeat Request AWGN Additive White Gaussian Noise BCCHBroadcast Control Channel BCH Broadcast Channel BWP Bandwidth Part CACarrier Aggregation CC Carrier Component CCCH SDU Common Control ChannelSDU CDMA Code Division Multiplexing Access CGI Cell Global IdentifierCIR Channel Impulse Response CP Cyclic Prefix CPICH Common Pilot ChannelCPICH Ec/No CPICH Received energy per chip divided by the power densityin the band CQI Channel Quality information CQIs Channel QualityIndicators C-RNTI Cell RNTI CRI CSI-RS Resource Indicator CSI ChannelState Information CSI-RS Channel State Information Reference Signal DCCHDedicated Control Channel DFT Discrete Fourier Transform DL Downlink DMDemodulation DMRS Demodulation Reference Signal DRX DiscontinuousReception DTX Discontinuous Transmission DTCH Dedicated Traffic ChannelDUT Device Under Test E-CID Enhanced Cell-ID (positioning method) E-SMLCEvolved-Serving Mobile Location Centre ECGI Evolved CGI eNB E-UTRANNodeB ePDCCH enhanced Physical Downlink Control Channel E-SMLC evolvedServing Mobile Location Center E-UTRA Evolved UTRA E-UTRAN Evolved UTRANFDD Frequency Division Duplex FFS For Further Study GERAN GSM EDGE RadioAccess Network gNB Base station in NR GNSS Global Navigation SatelliteSystem GSM Global System for Mobile communication HARQ Hybrid AutomaticRepeat Request HO Handover HSPA High Speed Packet Access HRPD High RatePacket Data IMR Interference Measurement Resource LOS Line of Sight LPPLTE Positioning Protocol LTE Long-Term Evolution MAC Medium AccessControl MBMS Multimedia Broadcast Multicast Services MBSFN MultimediaBroadcast multicast service Single Frequency Network MBSFN ABS MBSFNAlmost Blank Subframe MCS Modulation and Coding Scheme MDT Minimizationof Drive Tests MIB Master Information Block MIMO Multiple-Input MultipleOutput MME Mobility Management Entity MSC Mobile Switching CenterMU-MIMO Multi-User MIMO NPDCCH Narrowband Physical Downlink ControlChannel NR New Radio NZP Non-Zero Power OCNG OFDMA Channel NoiseGenerator OFDM Orthogonal Frequency Division Multiplexing OFDMAOrthogonal Frequency Division Multiple Access OSS Operations SupportSystem OTDOA Observed Time Difference of Arrival O&M Operation andMaintenance PBCH Physical Broadcast Channel P-CCPCH Primary CommonControl Physical Channel PCell Primary Cell PCFICH Physical ControlFormat Indicator Channel PDCCH Physical Downlink Control Channel PDPProfile Delay Profile PDSCH Physical Downlink Shared Channel PGW PacketGateway PHICH Physical Hybrid-ARQ Indicator Channel PLMN Public LandMobile Network PMI Precoder Matrix Indicator PRACH Physical RandomAccess Channel PRB Physical Resource Block PRG Precoding Resource blockGroup PRS Positioning Reference Signal PSS Primary SynchronizationSignal PUCCH Physical Uplink Control Channel PUSCH Physical UplinkShared Channel RACH Random Access Channel QAM Quadrature AmplitudeModulation RAN Radio Access Network RAT Radio Access Technology REResource Element RI Rank Indicator RLM Radio Link Management RNC RadioNetwork Controller RNTI Radio Network Temporary Identifier RRC RadioResource Control RRM Radio Resource Management RS Reference Signal RSCPReceived Signal Code Power RSRP Reference Symbol Received Power ORReference Signal Received Power RSRQ Reference Signal Received QualityOR Reference Symbol Received Quality RSSI Received Signal StrengthIndicator RSTD Reference Signal Time Difference SCH SynchronizationChannel SCell Secondary Cell SDU Service Data Unit SFN System FrameNumber SGW Serving Gateway SI System Information SIB System InformationBlock SNR Signal to Noise Ratio SON Self Optimized Network SSSynchronization Signal SSS Secondary Synchronization Signal TDD TimeDivision Duplex TDOA Time Difference of Arrival TFRE Time FrequencyResource Element TOA Time of Arrival TSS Tertiary Synchronization SignalTTI Transmission Time Interval UE User Equipment UL Uplink ULA UniformLinear Array UMTS Universal Mobile Telecommunication System UPA UniformPlanar Array USIM Universal Subscriber Identity Module UTDOA Uplink TimeDifference of Arrival UTRA Universal Terrestrial Radio Access UTRANUniversal Terrestrial Radio Access Network WCDMA Wide CDMA WLAN WideLocal Area Network

1-44. (canceled)
 45. A method performed by a wireless device fortransmitting channel state information, CSI, feedback using a multi-beamprecoder codebook, the method comprising: receiving a configuration fora sub-band channel quality indicator, CQI, granularity and a sub-bandprecoding matrix indicator, PMI, granularity for the wireless device,wherein the sub-band PMI granularity corresponds to a first sub-bandsize and the sub-band CQI granularity corresponds to a second sub-bandsize, wherein the first sub-band size is smaller than the secondsub-band size; and transmitting the CSI feedback to a base station,wherein the CSI feedback is in accordance with the configured sub-bandCQI granularity and the sub-band PMI granularity, wherein the CSIfeedback indicates a linear combination of precoder vectors, wherein theprecoder vectors correspond to respective frequency sub-bands having thefirst sub-band size, wherein the coefficients for the precoder vectorsin the linear combination of precoder vectors are parameterized in thefrequency-domain as a linear combination of a set of basis vectors and aset of coefficients for the basis vectors in the linear combination ofthe set of basis vectors.
 46. The method of claim 45, wherein theprecoder vectors are discrete Fourier transform, DFT, precoder vectors.47. The method of claim 45, wherein the CSI feedback is transmittedusing a new radio, NR, Type II multi-beam precoder codebook.
 48. Themethod of claim 45, wherein the CSI feedback is of new radio, NR,enhanced Type II.
 49. The method of claim 45, wherein the secondsub-band size is an integer multiple of the first sub-band size.
 50. Themethod of claim 45, wherein the sub-band CQI granularity configurationis obtained from a subbandSize radio resource control parameter in aCSI-ReportConfig.
 51. The method of claim 45, wherein the sub-band PMIgranularity is obtained from a CSI-ReportConfig using a subbandPMI-Sizeparameter.
 52. A method performed by a base station for receivingchannel state information, CSI, feedback using a multi-beam precodercodebook, the method comprising: receiving the CSI feedback from awireless device according to a sub-band channel quality indicator, CQI,granularity and a sub-band precoding matrix indicator, PMI, granularity,wherein the sub-band PMI granularity corresponds to a first sub-bandsize and the sub-band CQI granularity corresponds to a second sub-bandsize, wherein the CSI feedback indicates a linear combination ofprecoder vectors, wherein the precoder vectors correspond to respectivefrequency sub-bands having the first sub-band size, wherein thecoefficients for the precoder vectors in the linear combination ofprecoder vectors are parameterized in the frequency-domain as a linearcombination of a set of basis vectors and a set of coefficients for thebasis vectors in the linear combination of the set of basis vectors, andwherein the first sub-band size is smaller than the second sub-bandsize.
 53. The method of claim 52, further comprising: determining thesub-band CQI granularity; determining the sub-band PMI granularity; andconfiguring the wireless device with the sub-band CQI granularity andthe sub-band PMI granularity.
 54. The method of claims 52, wherein theprecoder vectors are discrete Fourier transform, DFT, precoder vectors,wherein the CSI feedback is received using a new radio, NR, Type IImulti-beam precoder codebook, and wherein the CSI feedback is of newradio, NR, enhanced Type II.
 55. A wireless device for transmittingchannel state information, CSI, feedback using a multi-beam precodercodebook, the wireless device comprising: a receiver; a transmitter; andprocessing circuitry coupled to the receiver and the transmitter,wherein the processing circuitry is configured to cause the wirelessdevice to: receive a configuration for a sub-band channel qualityindicator, CQI, granularity and a sub-band precoding matrix indicator,PMI, granularity for the wireless device, wherein the sub-band PMIgranularity corresponds to a first sub-band size and the sub-band CQIgranularity corresponds to a second sub-band size, wherein the firstsub-band size is smaller than the second sub-band size; and transmit theCSI feedback to a base station, wherein the CSI feedback is inaccordance with the configured sub-band CQI granularity and the sub-bandPMI granularity, wherein the CSI feedback indicates a linear combinationof precoder vectors, wherein the precoder vectors correspond torespective frequency sub-bands having the first sub-band size, whereinthe coefficients for the precoder vectors in the linear combination ofprecoder vectors are parameterized in the frequency-domain as a linearcombination of a set of basis vectors and a set of coefficients for thebasis vectors in the linear combination of the set of basis vectors. 56.The wireless device of claim 55, wherein the precoder vectors arediscrete Fourier transform, DFT, precoder vectors.
 57. The wirelessdevice of claim 55, wherein the CSI feedback is transmitted using a newradio, NR, Type II codebook.
 58. The wireless device claim 55, whereinthe CSI feedback is of new radio, NR, enhanced Type II.
 59. The wirelessdevice of claim 55, wherein the second sub-band size is an integermultiple of the first sub-band size.
 60. The wireless device of claim59, wherein the processing circuitry is configured to cause the wirelessdevice to obtain the sub-band CQI granularity configuration from asubbandSize radio resource control parameter in a CSI-ReportConfig. 61.The wireless device of claim 55, wherein the processing circuitry isconfigured to cause the wireless device to obtain the sub-band PMIgranularity from a CSI-ReportConfig using a subbandPMI-Size parameter.62. A base station for receiving channel state information, CSI,feedback using a multi-beam precoder codebook, the base stationcomprising: a receiver; a transmitter; and processing circuitry coupledto the receiver and the transmitter, wherein the processing circuitry isconfigured to cause the base station to: receive the CSI feedback from awireless device according to a sub-band channel quality indicator, CQI,granularity and a sub-band precoding matrix indicator, PMI, granularity,wherein the sub-band PMI granularity corresponds to a first sub-bandsize and the sub-band CQI granularity corresponds to a second sub-bandsize, wherein the CSI feedback indicates a linear combination ofprecoder vectors, wherein the precoder vectors correspond to respectivefrequency sub-bands having the first sub-band size, wherein thecoefficients for the precoder vectors in the linear combination ofprecoder vectors are parameterized in the frequency-domain as a linearcombination of a set of basis vectors and a set of coefficients for thebasis vectors in the linear combination of the set of basis vectors, andwherein the first sub-band size is smaller than the second sub-bandsize.
 63. The base station of claim 62, wherein the processing circuitryis further configured to cause the base station to: determine thesub-band CQI granularity; determine the sub-band PMI granularity; andconfigure the wireless device with the sub-band CQI granularity and thesub-band PMI granularity.
 64. The base station of claim 62, wherein theprecoder vectors are discrete Fourier transform, DFT, precoder vectors,wherein the CSI feedback is received using a new radio, NR, Type IImulti-beam precoder codebook, and wherein the CSI feedback is of newradio, NR, enhanced Type II.